Agile Principles, Patterns, and Practices in C#

[Booch94] Grady Booch, Object-Oriented Analysis and Design with Applications, 2d ed., Addison-Wesley, 1994.

[GOF95] Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, Design Patterns: Elements of Reusable Object-Oriented Software, Addison-Wesley, 1995.