Addison Wesley - The Design Patterns Java Companion (1998)

This book, commonly referred to as the Gang of Four or “GoF” book, has had a powerful impact on those seeking to understand how to use design patterns and has become an all-time best seller. We will refer to this groundbreaking book as Design Patterns, throughout this book and The Design Patterns Smalltalk Companion (Alpert, Brown and Woolf, 1998) as the Smalltalk Companion.