APA
Gamma E., Helm R., Johnson R. & Vlissides J. (1995). Design patterns: elements of reusable object-oriented software. Indianapolis, USA: Addison-Wesley.
Chicago
Gamma Erich, Helm Richard, Johnson Ralph and Vlissides John. 1995. Design patterns: elements of reusable object-oriented software. Indianapolis, USA: Addison-Wesley.
Harvard
Gamma E., Helm R., Johnson R. and Vlissides J. (1995). Design patterns: elements of reusable object-oriented software. Indianapolis, USA: Addison-Wesley.
MLA
Gamma Erich, Helm Richard, Johnson Ralph and Vlissides John. Design patterns: elements of reusable object-oriented software. Indianapolis, USA: Addison-Wesley. 1995.