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.