Design by Contract, by Example Richard Mitchell, Jim McKim, Addison Wesley, 2002 Designing Object-Oriented Software Rebeca Wirfs-Brock, Brian Wilkerson, Lauren Wiener, Prentice Hall, 1990 IT Architectures and Middleware Chris Britton, Addison Wesley, 2001 Object-Oriented Design Heuristics Arthur J. Riel, Addison-Wesley, 1996 Refactoring Martin Fowler, Addison-Wesley, 1999 The CRC Card Book David Bellin et al., Addison Wesley, 2000