\newcommand{\etalchar}[1]{$^{#1}$}
\begin{thebibliography}{CDG{\etalchar{+}}88}

\bibitem[Car89]{Card89}
L.~Cardelli.
\newblock Typeful Programming.
\newblock Digital Systems Research Center Reports~45, DEC SRC Palo Alto, May
  1989.

\bibitem[Car90]{Card90}
L.~Cardelli.
\newblock The Quest Language and System (Tracking Draft).
\newblock Digital systems research center, DEC SRC Palo Alto, 1990.
\newblock (shipped as part of the Quest V.12 system distribution).

\bibitem[CDG{\etalchar{+}}88]{Card88}
L.~Cardelli, J.~Donahue, L.~Glassman, M.~Jordan, B.~Kalsow, and G.~Nelson.
\newblock Modula-3 Report.
\newblock Technical Report ORC-1, Olivetti Research Center, 2882 Sand Hill
  Road, Memlo Park, California, 1988.

\bibitem[Mat91]{Matt91b}
F.~Matthes.
\newblock Tycoon Library Manual ({\it P-Quest} Version).
\newblock DBIS Tycoon Report 102-91, Fachbereich Informatik, Universit\"at
  Hamburg, West Germany, October 1991.

\bibitem[M"u91]{Mue91}
Rainer M"uller.
\newblock Sprachprozessoren und Objektspeicher: Schnittstellenentwurf und
  -implementierung.
\newblock Master's thesis, Fachbereich Informatik, Johann Wolfgang
  Goethe-Universit\"at, Frankfurt, West Germany, November 1991.

\bibitem[Wir85]{Wirt83}
N.~Wirth.
\newblock {\em Programming in Modula-2}.
\newblock Springer-Verlag, 1985.

\end{thebibliography}