Agile Principles, Patterns, and Practices in C#

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

[PLOPD1] James O. Coplien and Douglas C. Schmidt, Pattern Languages of Program Design, Addison-Wesley, 1995.