\begin{thebibliography}{10}

\bibitem{buneman-etal-94}
Peter Buneman, Leonid Libkin, Dan Suciu, Val Breazu-Tannen, and Limsoon Wong.
\newblock Comprehension syntax.
\newblock {\em ACM SIGMOD Record}, 23(1):87--96, March 1994.
\newblock
  \online{http://www.acm.org/sigs/sigmod/record/issues/9403/Comprehension.ps}.

\bibitem{oql}
Rick Cattell, Douglas Barry, Mark Berler, Jeff Eastman, David Jordan, Craig
  Russell, Olaf Schadow, Torsten Stanienda, and Fernando Velez, editors.
\newblock {\em Object Data Standard---ODMG 3.0}.
\newblock Morgan Kaufmann, January 2000.

\bibitem{zpl-regions}
Bradford Chamberlain, Christopher Lewis, Calvin Lin, and Lawrence Snyder.
\newblock Regions: An abstraction for expressing array computation.
\newblock In {\em Proceedings of the SIGAPL/SIGPLAN International Conference on
  Array Programming Languages}, pages 41--49, August 1999.
\newblock \online{http://www.cs.washington.edu/homes/echris/papers/apl99.ps}.

\bibitem{zpl-sparse-regions}
Bradford Chamberlain, Christopher Lewis, and Lawrence Snyder.
\newblock A region-based approach for sparse parallel computing.
\newblock Technical Report UW-CSE-98-11-01, University of Washington at Seattle
  (Computer Science), November 1998.
\newblock \online{ftp://ftp.cs.washington.edu/tr/1998/11/UW-CSE-98-11-01.PS.Z}.

\bibitem{codd-70}
Edgar~F. Codd.
\newblock A relational model of data for large shared data banks.
\newblock {\em Communications of the ACM}, 13(6):377--387, 1970.

\bibitem{codd-79}
Edgar~F. Codd.
\newblock Extending database relations to capture more meaning.
\newblock {\em ACM Transactions on Database Systems}, 4(4):397--434, 1979.

\bibitem{codd-book}
Edgar~F. Codd.
\newblock {\em The Relational Model for Database Management}.
\newblock Addison-Wesley, 1990.

\bibitem{rewriting-taste}
Nachum Dershowitz.
\newblock A taste of rewriting.
\newblock In Peter~E. Lauer, editor, {\em Functional Programming, Concurrency,
  Simulation and Automated Reasoning}, pages 199--228. Springer-Verlag, 1993.
\newblock
  \online{http://www-sal.cs.uiuc.edu/\~{}nachum/papers/taste-fixed.ps.gz}.

\bibitem{fegaras-maier-2000}
Leonidas Fegaras and David Maier.
\newblock Optimizing object queries using an effective calculus.
\newblock {\em ACM Transactions on Database Systems}, 25(4):?--?, December
  2000.
\newblock \online{http://lambda.uta.edu/tods00.ps.gz}.

\bibitem{opl-book}
{Pascal van} Hentenryck.
\newblock {\em The OPL Optimization Programming Language}.
\newblock The MIT Press, 1999.

\bibitem{ooql-principles}
Andreas Heuer and Marc~H. Scholl.
\newblock Principles of object-oriented query languages.
\newblock In H.-J. Appelrath, editor, {\em Proceedings of the GI Conference on
  Database Systems for Office, Scientific, and Engineering Applications,
  Kaiserslautern, Germany}, pages 178--197. Springer-Verlag IFB 270, 1991.
\newblock
  \online{ftp://ftp.informatik.uni-konstanz.de/pub/dbis/Publications/HS:BTW91.%
ps.gz}.

\bibitem{SQL}
James Hoffman.
\newblock Introduction to {S}tructured {Q}uery {L}anguage.
\newblock \online{http://w3.one.net/\~{}jhoffman/sqltut.htm}, 1996--2001.

\bibitem{k-b}
Donald~E. Knuth and Peter~B. Bendix.
\newblock Simple word problems in universal algebras.
\newblock In J.~Leech, editor, {\em Computational Problems in Abstract
  Algebra}, pages 263--297. Pergamon Press, Oxford, UK, 1970.
\newblock Reprinted in \emph{Automatic Reasoning}, 2, Springer-Verlag,
  pp.~342--276 (1983).

\bibitem{libkin-etal-96}
Leonid Libkin, Rona Machlin, and Limsoon Wong.
\newblock A query language for multidimensional arrays: Design, implementation,
  and optimization techniques.
\newblock In {\em Proceedings of the 1996 ACM SIGMOD International Conference
  on Management of Data, Montreal, Canada}, pages 228--239, May 1996.
\newblock \online{http://www.cs.toronto.edu/\~{}libkin/papers/sigmod96a.ps.gz}.

\bibitem{opl-critique}
Fr\'ed\'eric Paulin.
\newblock {OPL} language syntax critique and proposal for improvement.
\newblock \online{file:/nfs/opl/matisse/dev/opl\_syntax\_critic.html}, April
  2001.
\newblock ILOG internal access only.

\bibitem{vandenberg-phd}
Scott~L. Vandenberg.
\newblock {\em Algebras for Object-Oriented Query Languages}.
\newblock PhD thesis, University of Wisconsin at Madison (Computer Sciences),
  1993.
\newblock
  \online{ftp://ftp.cs.wisc.edu/pub/tech-reports/reports/1993/tr1161.ps.Z}.

\bibitem{wong-phd}
Limsoon Wong.
\newblock {\em Querying Nested Collections}.
\newblock PhD thesis, University of Pennsylvania (Computer and Information
  Science), 1994.
\newblock \online{ftp://ftp.cis.upenn.edu/pub/ircs/tr/94-09.ps.Z}.

\end{thebibliography}