Citazione Stile APA (7a Edizione)

Simpson, G. G. (1945). The principles of classification and a classification of mammals. American Museum of Natural History.

Citazione stile Chigago Style (17a edizione)

Simpson, George Gaylord. The Principles of Classification and a Classification of Mammals. New York: American Museum of Natural History, 1945.

Citatione MLA (9a ed.)

Simpson, George Gaylord. The Principles of Classification and a Classification of Mammals. American Museum of Natural History, 1945.