\newcommand{\etalchar}[1]{$^{#1}$}
\begin{thebibliography}{BMM{\etalchar{+}}91}

\bibitem[AB87]{AtBu86}
M.P. Atkinson and P.~Bunemann.
\newblock Types and Persistence in Database Programming Languages.
\newblock {\em ACM Computing Surveys}, 19(2), June 1987.

\bibitem[ABW{\etalchar{+}}90]{ABW*90}
M.~Atkinson, F.~Ban\c{c}ilhon, D.~De Witt, K.~Dittrich, D.~Maier, and
  S.~Zdonik.
\newblock The Object-Oriented Database System Manifesto.
\newblock In {\em Deductive and Object-oriented Databases}. Elsevier Science
  Publishers, Amsterdam, Netherlands, 1990.

\bibitem[BDK92]{BDK92}
F.~Bancilhon, C.~Delobel, and P.~Kanellakis.
\newblock {\em Building an Object-Oriented Database System: The Story of
  O$_{2}$}.
\newblock Morgan Kaufmann Publishers, 1992.

\bibitem[BHR82]{BHR82}
P.~Bunemann, J.~Hirschberg, and D.~Root.
\newblock A Codasyl Interface to Pascal and Ada.
\newblock In {\em Proc. 2nd British National Conference on Databases (BNCOD
  2)}. Cambridge University Press, 1982.

\bibitem[BL84]{BuLa84}
R.~Burstall and B.~Lampson.
\newblock A kernel language for abstract data types and modules.
\newblock In {\em Semantics of Data Types}, volume 173 of {\em Lecture Notes in
  Computer Science}. Springer-Verlag, 1984.

\bibitem[Bla90]{Blas90}
A.~Blaser, editor.
\newblock {\em Database Systems of the 90s}, volume 466 of {\em Lecture Notes
  in Computer Science}, November 1990.

\bibitem[BM91]{BaMy91}
R.~Balzer and J.~Mylopoulos.
\newblock International Workshop on the Develpment of Intelligent Information
  Systems.
\newblock Technical report, University of Southern California and University of
  Toronto, April 1991.

\bibitem[BMM{\etalchar{+}}91]{B*91}
A.L. Brown, G.~Mainetto, F.~Matthes, R.~M{\"u}ller, and D.J. McNally.
\newblock An Open System Architecture for a Persistent Object Store.
\newblock Persistent Programming Research Report CS/91/9, Univ. of St. Andrews,
  Dept. of Comp. Science, September 1991.

\bibitem[Car88]{Card88c}
L.~Cardelli.
\newblock Structural Subtyping and the Notion of Power Type.
\newblock In {\em Proceedings of the Fifteenth ACM Symposium on Principles of
  Programming Languages}, 1988.

\bibitem[Car89]{Card89}
L.~Cardelli.
\newblock Typeful Programming.
\newblock Report~45, DEC Systems Research Center, 130 Lytton Avenue, Palo Alto,
  94301 CA, May 1989.

\bibitem[Cat91]{Catt91}
R.G.G. Cattell.
\newblock Next-Generation Database Systems.
\newblock {\em Communications of the ACM}, 34(10), October 1991.

\bibitem[CH85]{CoHu85}
T.~Coquand and G.~Huet.
\newblock Constructions: a higher order proof system for mechanizing
  mathematics.
\newblock Technical Report 401, INRIA, Domaine de Voluceau Rocquencourt 78153
  Le Chesnay Cedex - France, May 1985.

\bibitem[CMA93]{CMA93}
L.~Cardelli, F.~Matthes, and M.~Abadi.
\newblock Extensible Grammars for Language Specialization.
\newblock In {\em Proceedings of the Fourth Workshop on Database Programming
  Languages}, Manhatten, NY, 1993. Springer-Verlag.
\newblock To appear.

\bibitem[CW85]{CaWe85}
L.~Cardelli and P.~Wegner.
\newblock On Understanding Types, Data Abstraction, and Polymorphism.
\newblock {\em ACM Computing Surveys}, 17(4):471--522, December 1985.

\bibitem[HW86]{HuWa92}
P.~Hudak and P.~Wadler.
\newblock Report on the Programming Language {Haskell} Version 1.2.
\newblock {\em SCM SIGPLAN Notices}, 21(7):219--233, July 1986.

\bibitem[{Inf}86]{Infor86}
{Informix Software Corp.}
\newblock Informix-4GL Reference Manual.
\newblock Technical report, {Informix Software Corp.}, 1986.

\bibitem[{Ing}89]{Ingb90}
{Ingres Corporation}.
\newblock INGRES ABF/4GL Reference Manual for the UNIX and VMS Operating
  Systems.
\newblock Technical Report INGRES Release 6.3, Ingres Corporation, 1080 Marina
  Village Parkway, Almeda, CA 94501, November 1989.

\bibitem[{Ing}90]{ESQL90}
{Ingres Corporation}.
\newblock INGRES Embedded SQL Companion Guide for C.
\newblock Technical Report INGRES UNIX Release 6.3, Ingres Corporation, 1080
  Marina Village Parkway, Almeda, CA 94501, December 1990.

\bibitem[KMP{\etalchar{+}}83]{Reim83}
J.~Koch, M.~Mall, P.~Putfarken, M.~Reimer, J.W. Schmidt, and C.A. Zehnder.
\newblock {Modula/R} Report, Lilith Version.
\newblock Technical report, Department Informatik, ETH Z\"urich, Switzerland,
  February 1983.

\bibitem[LLOW92]{LLOW92}
C.~Lamb, G.~Landis, J.~Orenstein, and D.~Weinreb.
\newblock The ObjectStore Database System.
\newblock {\em Communications of the ACM}, 34(10):50--64, 1992.

\bibitem[Mac86]{MacQ86}
D.B. MacQueen.
\newblock Using dependent types to express modular structure.
\newblock In {\em Conf. Record 13th Ann. Symp. Principles of Programming
  Languages}, pages 277--26. ACM, January 1986.

\bibitem[Mat93]{Matt93}
F.~Matthes.
\newblock {\em Persistente Objektsysteme: Integrierte Datenbankentwicklung und
  Programmerstellung}.
\newblock Springer-Verlag, 1993.
\newblock (In German).

\bibitem[MJ89]{MaJa89}
V.M. Matos and P.J. Jalics.
\newblock An Experimental Analysis of the Performance of 4GL Tools on PCs.
\newblock {\em Communications of the ACM}, 32(11):1340--1352, 1989.

\bibitem[ML75]{Mart75}
P.~Martin-L\"{o}f.
\newblock An intuitionistic theory of types: predicative part.
\newblock In H.E. Rose and J.C. Sheperdson, editors, {\em Logic Colloquium
  1973}, pages 73--118, Amsterdam, 1975. North Holland Publishing Company.

\bibitem[MMS92]{MMS92}
F.~Matthes, R.~M\"uller, and J.W. Schmidt.
\newblock Object Stores as Servers in Persistent Programming Environments --
  The P-Quest Experience.
\newblock FIDE Technical Report Series TR/92/48, Fachbereich Informatik,
  Universit\"at Hamburg, Germany, July 1992.

\bibitem[MS92]{MaSc92a}
F.~Matthes and J.W. Schmidt.
\newblock Definition of the Tycoon Language TL -- A Preliminary Report.
\newblock Informatik Fachbericht FBI-HH-B-160/92, Fachbereich Informatik,
  Universit\"at Hamburg, Germany, November 1992.

\bibitem[MTH90]{MTH90}
R.~Milner, M.~Tofte, and R.~Harper.
\newblock {\em The Definition of {Standard ML}}.
\newblock MIT Press, Cambridge, MA, 1990.

\bibitem[{Ora}91]{Orac90}
{Oracle Corporation}.
\newblock PL/SQL User's Guide and Reference, Version 1.0.
\newblock Technical Report Part No.~800-V1.0, Oracle Corporation, June 1991.

\bibitem[Sch77]{Schm77a}
J.W. Schmidt.
\newblock Some High Level Language Constructs for Data of Type Relation.
\newblock In {\em Proceedings of the ACM-SIGMOD International Conference on
  Management of Data, Toronto, Canada}, August 1977.

\bibitem[SM92a]{ScMa92a}
J.W. Schmidt and F.~Matthes.
\newblock The Database Programming Language {DBPL}: Rationale and Report.
\newblock FIDE Technical Report Series FIDE/92/46, Fachbereich Informatik,
  Universit\"at Hamburg, Germany, July 1992.

\bibitem[SM92b]{SchMa92}
G.~Schr\"oder and F.~Matthes.
\newblock Using the {Tycoon} Compiler Toolkit.
\newblock DBIS Tycoon Report 061-92, Fachbereich Informatik, Universit\"at
  Hamburg, Germany, May 1992.

\bibitem[SM93]{ScMa93}
J.W. Schmidt and F.~Matthes.
\newblock Lean Languages and Models: Towards an Interoperable Kernel for
  Persistent Object Systems.
\newblock In {\em Proceedings of the IEEE International Workshop on Research
  Issues in Data Engineering, Interoperability in Multidatabase Systems}, pages
  2--16, Vienna, Austria, April 1993.

\bibitem[SMV93]{SMV93}
J.W. Schmidt, F.~Matthes, and P.~Valduriez.
\newblock Building Persistent Application Systems in Fully Integrated Data
  Environments: Modularization, Abstraction and Interoperability.
\newblock In P.P. Spies, editor, {\em Proceedings Euro-Arch'93}, 1993.

\bibitem[SRL{\etalchar{+}}90]{Manifesto90}
M.~Stonebraker, L.A. Rowe, B.~Lindsay, J.~Gray, M.~Carey, M.~Brodie, and
  P.~Bernstein.
\newblock Third-Generation Data Base System Manifesto.
\newblock {\em ACM SIGMOD Record}, 19(3):31--44, September 1990.

\bibitem[ZM89]{ZdMa89}
S.B. Zdonik and D.~Maier.
\newblock {\em Readings in Object Oriented Database Management Systems}.
\newblock Morgan Kaufmann Publishers, 1989.

\end{thebibliography}