\begin{thebibliography}{100}

\bibitem{Adler87a}
{\sc I.~Adler}, {\em {Zur Spezifikation und Implementierung von finiten Element
  Netz\-generatoren}}, {Diplomarbeit}, Institut f\"ur Informatik, TU M\"unchen,
  May 1987.

\bibitem{Axelsson84a}
{\sc O.~Axelsson and V.~Barker}, {\em Finite element solutions of boundary
  value problems}, Academic Press, New York, 1984.

\bibitem{Babuska76a}
{\sc I.~{Babu\v{s}ka} and A.~Aziz}, {\em On the angle condition in the finite
  element method}, SIAM J. Numer. Anal., 13 (1976), pp.~214--226.

\bibitem{Babuska83a}
{\sc I.~{Babu\v{s}ka}, A.~Miller, and M.~Vogelius}, {\em Adaptive methods and
  error estimation for elliptic problems in structural mechanics}, in Adaptive
  Computational Methods for Partial Differential Equations, I.~{Babu\v{s}ka},
  J.~Chandra, and J.~Flaherty, eds., Society for Industrial and Applied
  Mathematics, Philadelphia, 1983.

\bibitem{Babuska81a}
{\sc I.~{Babu\v{s}ka}, B.~A. Szabo, and I.~Katz}, {\em The p-version of the
  finite element method}, SIAM J. Numer. Anal., 18 (1981), pp.~515--545.

\bibitem{Bai87a}
{\sc D.~Bai and A.~Brandt}, {\em Local mesh refinement multilevel techniques},
  SIAM J. Sci. Statist. Comput., 8 (1987), pp.~109--134.

\bibitem{Bank91a}
{\sc R.~Bank and M.~Benbourenane}, {\em The hierarchical basis multigrid method
  for convection-diffusion equations}, preprint, Department of Mathematics,
  University of California at San Diego, 1991.

\bibitem{Bank88a}
{\sc R.~Bank, T.~Dupont, and H.~Yserentant}, {\em The hierarchical basis
  multigrid method}, Numer. Math., 52 (1988), pp.~427--458.

\bibitem{Bank85b}
{\sc R.~Bank and A.~Weiser}, {\em Some a-posteriori estimators for elliptic
  partial differential equations}, Math. Comp., 44 (1985), pp.~283--301.

\bibitem{Bank90a}
{\sc R.~E. Bank}, {\em {PLTMG:} A Software Package for Solving Elliptic Partial
  Differential Equations}, Frontiers in Applied Mathematics, Vol. 7,
  Society for Industrial and Applied Mathematics, Philadelphia, 1990.

\bibitem{Baensch91a}
{\sc E.~{B\"ansch}}, {\em Local mesh refinement in {\rm 2} and {\rm 3}
 dimensions}, IMPACT of Computing in Science and Engineering, 
 3 (1991), pp.~181--191.

\bibitem{Bastian92a}
{\sc P.~Bastian}, {\em Locally refined solution of unsymmetric and nonlinear
  problems}, in Incomplete Decompositions: Proceedings of the Eigth
  GAMM-Seminar, Notes in Numerical Fluid Mechanics, Vol. 41, 
  Vieweg-Verlag, Braunschweig, 1992, pp.~12--21.

\bibitem{Bauer84a}
{\sc F.~Bauer and H.~W\"{o}ssner}, {\em Algorithmische Sprache und
  Programmentwicklung}, 2.~Auf\/lage, Springer-Verlag, 1984.
\newblock{English translation: Algorithmic Language and Program
  Development}.

\bibitem{Bause90a}
{\sc F.~Bause and W.~{T\"olle}}, {\em {C++ f\"ur Programmierer}}, 
Vieweg-Verlag, Braunschweig, 1990.

\bibitem{Besov90a}
{\sc O.~Besov, L.~Kudrayavtsev, P.~Lizorkin, and S.~{Nikol'ski\u{\i}}}, {\em
  Investigations in the theory of spaces of differentiable functions of several
  variables}, Proceedings of the Steklov Institute of Mathematics, 
  St.\ Petersburg, Russia, 1990.

\bibitem{Blum91a}
{\sc H.~Blum}, {\em Asymptotic error expansion and defect correction in the
  finite element method},
\newblock Habilitationsschrift, Universit\"{a}t Heidelberg, 1991.

\bibitem{Blum86a}
{\sc H.~Blum, Q.~Lin, and R.~Rannacher}, {\em Asymptotic error expansions and
  {Richardson} extrapolation for linear finite elements}, Numer.~Math., 49
  (1986), pp.~11--37.

\bibitem{Blum88a}
{\sc H.~Blum and R.~Rannacher}, {\em Extrapolation techniques for reducing the
  pollution effect of reentrant corners in the finite element method},
  Numer.~Math., 52 (1988), pp.~539--564.

\bibitem{Bonk92a}
{\sc T.~Bonk and U.~{R\"ude}}, {\em Performance analysis and optimization of
  numerically intensive programs}, SFB Bericht 342/26/92 A, Institut f\"ur
  Informatik, TU M\"unchen, November 1992.

\bibitem{Bornemann92d}
{\sc F.~Bornemann and H.~Yserentant}, {\em A basic norm equivalence for the
  theory of multilevel methods}, Numer.\ Math., 64 (1993), pp.~455--476.

\bibitem{Braess92a}
{\sc D.~Braess}, {\em Finite Elemente}, Springer-Verlag, Berlin, 1992.

\bibitem{Braess83a}
{\sc D.~Braess and W.~Hackbusch}, {\em A new convergence proof for the
  multigrid method including the {V}-cycle}, SIAM J. Numer. Anal., 20 (1983),
  pp.~967--975.

\bibitem{Bramble89b}
{\sc J.~Bramble, J.~Pasciak, J.~Wang, and J.~Xu}, {\em Convergence estimates
  for multigrid algorithms without regularity assumptions}, Report BNL-44512,
  Brookhaven National Laboratory, New York, August 1989.

\bibitem{Bramble89a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Convergence
  estimates for product iterative methods with applications to domain
  decomposition and multigrid}, Report BNL-44511, Brookhaven National
  Laboratory, New York, August 1989.

\bibitem{Bramble90a}
{\sc J.~Bramble, J.~Pasciak, and J.~Xu}, {\em Parallel multilevel
  preconditioners}, Math. Comp., 31 (1990), pp.~333--390.

\bibitem{Bramble91a}
{\sc J.~H. Bramble, J.~E. Pasciak, and J.~Xu}, {\em The analysis of multigrid
  algorithms with nonnested spaces or noninherited quadratic forms}, Math.
  Comp., 56 (1991), pp.~1--34.

\bibitem{Brandt77a}
{\sc A.~Brandt}, {\em Multi-level adaptive solutions to boundary value
  problems}, Math. Comp., 31 (1977), pp.~333--390.

\bibitem{Brandt84a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Multigrid
  techniques: {\rm 1984} guide with applications to fluid dynamics}, 
  GMD Studien, Vol.\ 85, 1984.

\bibitem{Brandt86b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Algebraic multigrid
  theory: {The} symmetric case}, Appl. Math. Comp., 19 (1986), pp.~23--65.

\bibitem{Brandt89a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Rigorous local mode
  analysis of multigrid}, in Preliminary Proceedings of the Fourth Copper
  Mountain Conference on Multigrid Methods, University of Colorado at Denver,
  April 9--14, 1989, S.~McCormick, ed.

\bibitem{Brandt83b}
{\sc A.~Brandt and D.~Ophir}, {\em Gridpack}, in Proceedings IFIP Conference on
  PDE Software, Solderkoping, Sweden, 1983.

\bibitem{Briggs87a}
{\sc W.~L. Briggs}, {\em A Multigrid Tutorial}, Society for Industrial
  and Applied Mathematics, Philadelphia, 1987.

\bibitem{Ciarlet78a}
{\sc P.~Ciarlet}, {\em The Finite Element Method for Elliptic Problems},
  North-Holland, Amsterdam, New York, London, 1978.

\bibitem{Dahmen91a}
{\sc W.~Dahmen and A.~Kunoth}, {\em Multilevel preconditioning}, Numer. Math.,
  63 (1992), pp.~315--344.

\bibitem{Deuflhard89a}
{\sc P.~Deuflhard, P.~Leinen, and H.~Yserentant}, {\em Concepts of an adaptive
  hierarchical finite element code}, IMPACT of Computing in Science and
  Engineering, 1 (1989), pp.~3--35.

\bibitem{Dewhurst89a}
{\sc S.~Dewhurst and K.~Stark}, {\em Programming in {C++}}, Prentice Hall,
  Englewood Cliffs, NJ, 1989.

\bibitem{Dryja87a}
{\sc M.~Dryja and O.~Widlund}, {\em An additive variant of the {Schwarz}
  alternating method for the case of many subregions}, Tech. Report 339 and
  Ultracomputer Note 131, Department of Computer Science,
  Courant Institute, 1987.

\bibitem{Dryja91a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Multilevel additive
  methods for elliptic finite element problems}, in Parallel Algorithms for
  Partial Differential Equations, Proceedings of the Sixth GAMM-Seminar, Kiel,
  January 19--21, 1990, W.~Hackbusch, ed.,  Vieweg-Verlag,
  Braunschweig, 1991.

\bibitem{George81a}
{\sc A.~George and W.~Liu}, {\em Computer Solution of Large Sparse Positive
  Definite Systems}, Prentice Hall, Englewood Cliffs, NJ, 1981.

\bibitem{Griebel90d}
{\sc M.~Griebel}, {\em Zur {L\"osung} von {Finite-Dif\-feren\-zen-} und
  {Finite-\-Ele\-ment-\-Gleichun\-gen} mittels der
  {Hierar\-chi\-schen-\-Trans\-for\-mations-\-Mehr\-git\-ter-\-Metho\-de}}, SFB
  Bericht 342/4/90 A, Institut f\"ur Informatik, TU M\"unchen, February 1990.

\bibitem{Griebel91e}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Multilevel
  algorithms considered as iterative methods on indefinite systems}, SFB
  Bericht 342/29/91 A, Institut f\"ur Informatik, TU M\"unchen, October 1991;
\newblock see also Preliminary Proceedings of the Second Copper Mountain
  Conference on Iterative Methods.

\bibitem{Griebel92d}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Grid- and
  point-oriented multilevel algorithms}, SFB Bericht 342/14/92 A, Institut
  f\"ur Informatik, TU M\"unchen, July 1992.

\bibitem{Hackbusch85a}
{\sc W.~Hackbusch}, {\em Multigrid Methods and Applications}, Springer-Verlag,
  Berlin, 1985.

\bibitem{Hackbusch86a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Theorie und Numerik
  elliptischer Differentialgleichungen}, Teubner Studien\-b\"{u}cher,
  Stuttgart, 1986.

\bibitem{Hemker90a}
{\sc P.~Hemker, H.~{van~der~Maarel}, and C.~Everaars}, {\em {BASIS}: A data
  structure for adaptive multigrid computations}, Report NM-R9014, Department
  of Numerical Mathematics, Centrum for Wiskunde en Informatica, 
  Amsterdam, August 1990.

\bibitem{Hempel91a}
{\sc R.~Hempel and H.~Ritzdorf}, {\em The {GMD} communications library for
  grid--oriented problems}, Arbeitspapiere der GMD 589, Gesellschaft f\"ur
  Mathematik und Datenverarbeitung, St. Augustin, 1991.

\bibitem{Ruede88d}
{\sc C.~R. J\"{a}nsch, U.~R\"{u}de, and K.~Schnepper}, {\em Macro expansion, a
  tool for the systematic development of scientific software}, Bericht I-8814,
  Institut f\"{u}r Informatik, TU M\"{u}nchen, November 1988.

\bibitem{Johnen77a}
{\sc H.~Johnen and K.~Scherer}, {\em On the equivalence of the {K}-functional
  and the moduli of continuity and some applications}, Lecture Notes
  in Mathematics 571, Springer-Verlag, New York, 1977, pp.~119--140.

\bibitem{Leinen90a}
{\sc P.~Leinen}, {\em {Ein schneller adaptiver L\"{o}ser f\"{u}r elliptische
  Randwertprobleme auf Seriell- und Parallelrechnern}}, {Dissertation},
  Universit\"{a}t Dortmund, 1990.

\bibitem{Leinen91a}
{\sc P.~Leinen and H.~Yserentant}, Private communication, 1991.

\bibitem{Lemke92a}
{\sc M.~Lemke and D.~Quinlan}, {\em {P++}, a {C++} virtual shared grids based
  programming environment for architecture-independent development of
  structured grid applications}, {Arbeitspapiere der GMD} 611, {Gesellschaft
  f\"ur Mathematik und Datenverarbeitung}, St.\ Augustin, Germany,
  February 1992.

\bibitem{Loehner86a}
{\sc R.~L\"{o}hner and K.~Morgan}, {\em Unstructured multigrid methods}, in
  Multigrid Methods: Special Topics and Applications, Papers presented at the
  Second European Conference on Multigrid Methods, Cologne, October 1--4, 
  1985, U.~Trottenberg and W.~Hackbusch, eds.,  GMD Studien, Vol.\ 110,
  1986.

\bibitem{Luenberger73a}
{\sc D.~Luenberger}, {\em Introduction to linear and nonlinear programming},
  Addison-Wesley, Reading, MA, 1973.

\bibitem{Marchuk83a}
{\sc G.~Marchuk and V.~Shaidurov}, {\em Difference Methods and Their
  Extrapolations}, Springer-Verlag, New York, 1983.

\bibitem{McBryan91a}
{\sc O.~McBryan, P.~Frederickson, J.~Linden, A.~Sch\"uller, K.~Solchenbach,
  K.~{St\"uben}, C.-A. Thole, and U.~Trottenberg}, {\em Multigrid methods on
  parallel computers---a survey of recent developments}, IMPACT of Computing
  in Science and Engineering, 3 (1991), pp.~1--75.

\bibitem{McCormick87a}
{\sc S.~McCormick, ed.}, {\em Multigrid Methods}, Frontiers in
  Applied Mathematics, Vol.\ 3, Society for Industrial and Applied
  Mathematics, Philadelphia, 1987.

\bibitem{McCormick89b}
{\sc S.~McCormick}, {\em Multilevel Adaptive Methods for Partial Differential
  Equations}, Frontiers in Applied Mathematics, Vol.~6, Society for 
  Industrial and Applied Mathematics, Philadelphia, 1989.

\bibitem{McCormick92a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Multilevel
  Projection Methods for Partial Differential Equations}, CBMS-NSF Regional
  Conference Series in Applied Mathematics, Society for Industrial and Applied
  Mathematics, Philadelphia, 1992.

\bibitem{McCormick90a}
{\sc S.~McCormick and U.~R\"{u}de}, {\em On local refinement higher order
  methods for elliptic partial differential equations}, Internat. J.
  High Speed Comput., 2 (1990), pp.~311--334;
\newblock also available as TU-Bericht I-9034, Institut f\"ur Informatik,
  TU M\"unchen, September 1990.

\bibitem{McCormick82a}
{\sc S.~McCormick and J.~Ruge}, {\em Multigrid methods for variational
  problems}, SIAM J.~Numer.\ Anal., 19 (1982), pp.~924--927.

\bibitem{McCormick83a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Unigrid for
  multigrid simulation}, Math. Comp., 41 (1983), pp.~43--62.

\bibitem{McCormick86a}
{\sc S.~McCormick and J.~Thomas}, {\em The fast adaptive composite grid 
  {\rm (}FAC\/{\rm )} method for elliptic equations}, Math. Comp., 46 (1986),
  pp.~439--456.

\bibitem{Mikulinsky92a}
{\sc V.~Mikulinsky}, {\em Multigrid Treatment of Boundary and Free-Boundary
  Conditions}, Ph.D. thesis, The Weizmann Institute of Science, 
  Rehovot, Israel, 1992.

\bibitem{Mitchell91a}
{\sc W.~Mitchell}, {\em Adaptive refinement for arbitrary finite element spaces
  with hierarchical bases}, J. Comp. Appl. Math., 36 (1991), pp.~65--78.

\bibitem{Mitchell92a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Optimal multilevel
  iterative methods for adaptive grids}, SIAM J. Sci.~Statist.~Comput., 
  13 (1992), pp.~146--167;
\newblock also in Proceedings of the First Copper Mountain 
  Conference on Iterative Methods, April 1--5, 1990, T. Manteuffel, ed.

\bibitem{Nikolskii75a}
{\sc S.~{Nikol'ski\u{\i}}}, {\em Approximation of Functions of Several
  Variables and Imbedding Theorems}, Springer-Verlag, New York, 1975
\newblock (translated from {Russian}).

\bibitem{Ostrowski56a}
{\sc A.~Ostrowski}, {\em {Determinanten mit \"uberwiegender Hauptdiagonale und
  die absolute Konvergenz von linearen Iterationsprozessen}}, Comment.\
  Math.\ Helv., 30 (1956), pp.~175--210.

\bibitem{Oswald89b}
{\sc P.~Oswald}, {\em On {$C^1$}-interpolating hierarchical spline bases},
  Tech. Report N/89/19, {Friedrich Schiller Universit\"{a}t}, Jena, July 1989.

\bibitem{Oswald89a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em On estimates for
  hierarchic basis representations of finite element functions}, Tech. Report
  N/89/16, {Friedrich Schiller Universit\"{a}t}, Jena, June 1989.

\bibitem{Oswald90a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em On function spaces
  related to finite element approximation theory}, {Z.\
  Anal. Anwendungen}, 9 (1990), pp.~43--64.

\bibitem{Oswald90b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em On the degree of
  nonlinear spline approximation in {Besov-Sobolev} spaces}, J.\
  Approxim.\ Theory, 61 (1990), pp.~131--157.

\bibitem{Oswald91c}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em On discrete norm
  estimates related to multilevel preconditioners in the finite element
  method}, in Proceedings of International Conference on Constructive 
 Theory of Functions, Varna 1991, Bulgarian Academy of Science, Sofia,
  K.\ Ivanov and B.\ Sendov, 1992, pp.~203--241.

\bibitem{Oswald91d}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Preconditioners for
  discretizations of the biharmonic equation by rectangular finite elements},
  Forschungsergebnisse Math/91/03, {Friedrich Schiller Universit\"{a}t}, Jena,
  November 1991.

\bibitem{Oswald91b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Two remarks on
  multilevel preconditioners}, Forschungsergebnisse Math/91/1, {Friedrich
  Schiller Universit\"at}, Jena, 1991.

\bibitem{Oswald92a}
{\sc P.~Oswald}, {\em Norm equivalencies
  and multilevel Schwarz preconditioning for variational problems},
  Forschungsergebnisse Math/92/01, {Friedrich Schiller Universit\"{a}t}, Jena,
  January 1992.

\bibitem{Oswald92b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Stable splittings of
  {Sobolev} spaces and fast solution of variational problems},
  Forschungsergebnisse Math/92/05, {Friedrich Schiller Universit\"{a}t}, Jena,
  May 1992.

\bibitem{Pavarino92a}
{\sc L.~Pavarino}, {\em Some {S}chwarz algorithms for the p-version of the
  finite element method}, Tech. Report 614, Department of Computer Science,
  Courant Institute,  New York University,   1992.

\bibitem{Quateroni91a}
{\sc A.~Quarteroni}, {\em Domain decomposition and parallel processing for the
  numerical solution of partial differential equations}, Surv.~Math.~Ind., 1
  (1991), pp.~75--118.

\bibitem{Regler93a}
{\sc H.~Regler and U.~R{\"u}de}, {\em Layout optimization with algebraic
  multigrid methods {\rm (}AMG\/{\rm )}}, in Proceedings of the Sixth Copper Mountain
  Conference on Multigrid Methods, Copper Mountain, April 4--9, 1993, Conference
  Publication, NASA, 1993.

\bibitem{Rivara84a}
{\sc M.~Rivara}, {\em Algorithms for refining triangular grids suitable for
  adaptive and multigrid techniques}, Internat.\ J.\ Numer.\
  Methods Engrg., 20 (1984), pp.~745--756.

\bibitem{Rivara84b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Design and data
  structure of fully adaptive, multigrid, finite-element software}, ACM
  Trans.\ Math.\ Software, 10 (1984), pp.~242--264.

\bibitem{Roitzsch89a}
{\sc R.~Roitzsch}, {\em Kaskade user's manual}, Tech.\ Report TR 89-4,
  Konrad-Zuse-Zentrum f\"ur Informationstechnik, Berlin, August 1989.

\bibitem{Ruede87a}
{\sc U.~R\"{u}de}, {\em Multiple tau-extrapolation for multigrid methods},
  Bericht I-8701, Institut f\"{u}r Informatik, TU M\"{u}nchen, January 1987.

\bibitem{Ruede88a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em On the accurate
  computation of singular solutions of {Laplace's and Poisson's} equation}, in
  Multigrid Methods: Theory, Applications, Supercomputing: Proceedings of the
  Third Copper Mountain Conference on Multigrid Methods, April 5--10, 1987,
  S.~McCormick, ed., Marcel Dekker, New York, 1988.

\bibitem{Ruede91b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Extrapolation and
  related techniques for solving elliptic equations}, Bericht I-9135, Institut
  f\"{u}r Informatik, TU M\"{u}nchen, September 1991.

\bibitem{Ruede92d}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Data structures for
  multilevel adaptive methods and iterative solvers}, Bericht I-9217, Institut
  f\"{u}r Informatik, TU M\"{u}nchen, May 1992.

\bibitem{Ruede92a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em The hierarchical
  basis extrapolation method}, SIAM J. Sci.~Statist.~Comput., 13 (1992),
  pp.~307--318;
\newblock also in Proceedings of the First Copper Mountain Conference on Iterative
  Methods, April 1--5, 1990, T.\ Manteuffel, ed.

\bibitem{Ruede92e}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em On the multilevel
  adaptive iterative method}, in Preliminary Proceedings of the Second Copper
  Mountain Conference on Iterative Methods, April 9--14, 1992, T.~Manteuffel,
  ed.; SIAM J.~Sci.~Comput., 15 (1994), to appear.

\bibitem{Ruede93b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Data abstraction
  techniques for multilevel algorithms}, in Proceedings of the GAMM-Seminar on
  Multigrid Methods, in Gosen, Germany, Sept. 21--25, 1992; 
  Report 5, Institut f{\"u}r Angewandte Analysis und Stochastik, Berlin,
  1993. ISSN 0942--9077.

\bibitem{Ruede93c}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Extrapolation
  techniques for constructing higher order finite element methods}, Bericht
  I-9304, Institut f\"{u}r Informatik, TU M\"{u}nchen, 1993;
 SIAM J.~Numer.~Anal., submitted.

\bibitem{Ruede93a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Fully adaptive
  multigrid methods}, SIAM J. Numer. Anal., 30 (1993), pp.~230--248.

\bibitem{Ruede92b}
{\sc U.~R\"{u}de and C.~Zenger}, {\em On the treatment of singularities in the
  finite element method}, Bericht I-9220, Institut f\"{u}r Informatik, TU
  M\"{u}nchen, August 1992.

\bibitem{Schwarz91b}
{\sc H.~Schwarz}, {\em Methode der Finiten Elemente}, 3.~Auflage,
 Teubner {Studienb\"ucher} Mathematik, Teubner, Stuttgart, 1991.
 
\bibitem{Seidel74a}
{\sc L.~Seidel}, {\em {\"Uber ein Verfahren, die Gleichungen, auf welche die
  Methode der kleinsten Quadrate f\"uhrt, sowie lineare Gleichungen
  \"uberhaupt, durch successive Ann\"aherung zu l\"osen}}, Abh. Bayer. Akademie
  der Wiss. Math. Nat. Kl. 11,  1874.

\bibitem{Sewell79a}
{\sc E.~Sewell}, {\em A finite element program with automatic user-controlled
  mesh grading}, in Advances in Computer Methods for Partial Differential
  Equations {III}, R.~Vichnevetsky and R.~Stapleman, eds., IMACS, 
  New Brunswick, NJ, 1979, pp.~8--10.

\bibitem{Southwell35a}
{\sc R.~Southwell}, {\em Stress-calculation in frameworks by the method of
  systematic relaxation of constraints}, {Parts {\rm I, II}}, Proc. Roy. Soc. (A),
  (1935), pp.~56--95.

\bibitem{Southwell35b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Stress-calculation
  in frameworks by the method of ``systematic relaxation of constraints,''}
  {Part {\rm III}}, Proc. Roy. Soc. (A),  (1935), pp.~41--76.

\bibitem{Southwell40a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Relaxation Methods
  in Engineering Science---a Treatise in Approximate Computation}, Oxford
  University Press, 1940.

\bibitem{Southwell46a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Relaxation Methods
  in Theoretical Physics}, Clarendon Press, Oxford, 1946.

\bibitem{Stark89a}
{\sc M.~Stark}, {\em {Spezifikation und Implementierung einer Datenstruktur
  f\"ur dreidimensionale finite Elemente}}, {Diplomarbeit}, Institut f\"ur
  Informatik, TU M\"unchen, May 1989.

\bibitem{Stevenson90a}
{\sc R.~Stevenson}, {\em On the Validity of Local Mode Analysis of Multi-Grid
  Methods}, Ph.D.\ thesis, University of Utrecht, the Netherlands, 1990.

\bibitem{Strang73a}
{\sc G.~Strang and G.~Fix}, {\em An Analysis of the Finite Element Method},
  Prentice-Hall, Englewood Cliffs, NJ, 1973.

\bibitem{Stroustrup91a}
{\sc B.~Stroustrup}, {\em The {C++} Programming Language}, Second Ed.,
 Addison-Wesley,  Reading, MA, 1991.

\bibitem{Triebel78a}
{\sc H.~Triebel}, {\em Interpolation Theory, Function Spaces, Differential
  Operators}, North Holland, Amsterdam, 1978.

\bibitem{Triebel83a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Theory of Function
  Spaces}, Monographs in Mathematics, Vol.\ 78, Birkh{\"a}user-Verlag, Basel,
  1983.

\bibitem{Verfurth93}
{\sc R. Verf{\"u}rth}, {\em A review of a posteriori error estimation and
adaptive mesh-refinement techniques}, Lecture Notes of a Compact Seminar at
the TU Magdeburg, June 2--4, 1993; also Report, Universit{\"a}t Z{\"u}rich.

\bibitem{Widlund89a}
{\sc O.~B. Widlund}, {\em Optimal iterative refinement methods}, in Domain
  Decomposition Methods, T.~F. Chan, R.~Glowinsky, J.~P\'{e}riaux, and O.~B.
  Widlund, eds., Society for Industrial and Applied Mathematics,
  Philadelphia, 1989.

\bibitem{Xu89a}
{\sc J.~Xu}, {\em Theory of multilevel methods}, Report AM48, Department of
  Mathematics, Pennsylvania State University, State College, PA, July 1989.

\bibitem{Xu90a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Iterative methods by
  space decomposition and subspace correction: A unifying approach}, Report
  AM67, Department of Mathematics, Pennsylvania State University, 
  State College, PA 1990.

\bibitem{Xu92a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em A new class of
  iterative methods for nonselfadjoint or indefinite problems}, SIAM J. Numer.
  Anal., 29 (1992), pp.~303--319.

\bibitem{Yserentant86b}
{\sc H.~Yserentant}, {\em On the multi-level splitting of finite element
  spaces}, Numer. Math., 49 (1986), pp.~379--412.

\bibitem{Yserentant90b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Two preconditioners
  based on the multi-level splitting of finite element spaces}, Numer. Math.,
  58 (1990), pp.~163--184.

\bibitem{Yserentant91b}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Hierarchical bases},
  in Proceedings of the ICIAM 1991, Society for Industrial and Applied
  Mathematics, 1992.

\bibitem{Yserentant93a}
\leavevmode\vrule height 2pt depth -1.6pt width 23pt, {\em Old and new
  convergence proofs for multigrid methods}, Acta Numerica,  (1993),
  pp.~285--326.

\bibitem{Zhang88a}
{\sc S.~Zhang}, {\em Multilevel iterative techniques}, {Report}, Department of
  Mathematics, Pennsylvania State University, State College, PA, 1988.

\bibitem{Zhang91a}
{\sc X.~Zhang}, {\em Multilevel additive {Schwarz} methods}, Tech. Report 582,
Department of Computer Science, Courant Institute, New York University,  1991.
\end{thebibliography}