APA (7th ed.) Citation

Gamma Erich. (1995). Design petterns: Elements of reusable object-oriented software. Addison-Wesley.

Chicago Style (17th ed.) Citation

Gamma Erich. Design Petterns: Elements of Reusable Object-oriented Software. Addison-Wesley, 1995.

MLA (8th ed.) Citation

Gamma Erich. Design Petterns: Elements of Reusable Object-oriented Software. Addison-Wesley, 1995.

Warning: These citations may not always be 100% accurate.