References

1

David Ascher.
Snow.
http://starship.python.net:9673/crew/da/Code/Snow.

2

Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides.
Design Patterns.
Addison Wesley, Reading, MA, 1995.

3

Joseph J. Strout.
Piddle: A cross-platform drawing library.
http://www.strout.net/python/piddle.