1\begin{thebibliography}{Wielemaker \& Anjewierden, 1994}
2
3\bibitem[Anjewierden, 1992]{XPCE:lisp}
4A.~Anjewierden.
5\newblock {\em {XPCE/Lisp}: {XPCE Common Lisp} Interface}.
6\newblock {SWI}, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam,
7  The Netherlands, 1992.
8\newblock E-mail: anjo@swi.psy.uva.nl.
9
10\bibitem[Anjewierden {\em et al.}, 1990]{Anjewierden:90b}
11A.~Anjewierden, J.~Wielemaker, and C.~Toussaint.
12\newblock Shelley --- computer aided knowledge engineering.
13\newblock In B.~Wielinga, J.~Boose, B.~Gaines, G.~Schreiber, and M.~van
14  Someren, editors, {\em {Current trends in knowledge acquisition}}, pages 41
15  -- 59, Amsterdam, May 1990. IOS Press.
16
17\bibitem[Chambers {\em et al.}, 1989]{chambers:89}
18Craig Chambers, David Ungar, and Elgin Lee.
19\newblock An efficient implementation of {SELF}, a dynamic-typed
20  object-oriented language based on prototypes.
21\newblock {\em Sigplan Notices}, 24(10):49--70, Oct 1989.
22
23\bibitem[Goldberg \& Robson, 1983]{Goldberg:83a}
24A.~Goldberg and D.~Robson.
25\newblock {\em {Smalltalk--80: The Language and its Implementation}}.
26\newblock Addison-Wesley, 1983.
27
28\bibitem[Wielemaker \& Anjewierden, 1989]{Wielemaker:89}
29J.~Wielemaker and A.~Anjewierden.
30\newblock {Separating User Interface and Functionality Using a Frame Based Data
31  Model}.
32\newblock In {\em Proceedings Second Annual Symposium on User Interface
33  Software and Technology}, pages 25--33, Williamsburg, Virginia, November
34  1989. ACM Press.
35
36\bibitem[Wielemaker \& Anjewierden, 1993]{XPCE:reference}
37J.~Wielemaker and A.~Anjewierden.
38\newblock {\em {XPCE-4} Reference Manual}.
39\newblock {SWI}, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam,
40  The Netherlands, 1993.
41\newblock Paper version of online manual.
42
43\bibitem[Wielemaker \& Anjewierden, 1994]{XPCE:cpp}
44J.~Wielemaker and A.~Anjewierden.
45\newblock {\em A {C++} interface for {XPCE}}.
46\newblock {SWI}, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam,
47  The Netherlands, 1994.
48\newblock E-mail: jan@swi.psy.uva.nl.
49
50\bibitem[Wielemaker, 1992]{XPCE:draw}
51J.~Wielemaker.
52\newblock {\em {PceDraw}: An example of using {XPCE-4}}.
53\newblock {SWI}, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam,
54  The Netherlands, 1992.
55\newblock E-mail: jan@swi.psy.uva.nl.
56
57\bibitem[Wielemaker, 1994]{XPCE:course}
58J.~Wielemaker.
59\newblock {\em {XPCE/Prolog} Course Notes}.
60\newblock {SWI}, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam,
61  The Netherlands, 1994.
62\newblock E-mail: jan@swi.psy.uva.nl.
63
64\bibitem[Wielemaker, 1996]{SWI-Prolog:manual}
65J.~Wielemaker.
66\newblock {\em {SWI-Prolog 2.5}: Reference Manual}.
67\newblock {SWI}, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam,
68  The Netherlands, 1996.
69\newblock E-mail: jan@swi.psy.uva.nl.
70
71\end{thebibliography}
72