APA Style

Gamma, Erich, Helm, Richard, Johnson, Ralph, Vlissides, John. (2004). Design patterns:elements of reusable object-oriented software . Boston: addison wesley.

Chicago Style

Gamma, Erich, Helm, Richard, Johnson, Ralph, Vlissides, John. Design patterns:elements of reusable object-oriented software. Boston: addison wesley, 2004. Text.

MLA Style

Gamma, Erich, Helm, Richard, Johnson, Ralph, Vlissides, John. Design patterns:elements of reusable object-oriented software. Boston: addison wesley, 2004. Text.

Turabian Style

Gamma, Erich, Helm, Richard, Johnson, Ralph, Vlissides, John. Design patterns:elements of reusable object-oriented software. Boston: addison wesley, 2004. Print.