Citazione APA

Perrin,William F, & Wursig,Bernd Thewissen, J. (2009). Encyclopedia of marine mammals (2nd ed.). Elsevier.

Stile di citazione Chicago

Perrin,William F, e J.G.M Wursig,Bernd Thewissen. Encyclopedia of Marine Mammals. 2nd ed. Amsterdam: Elsevier, 2009.

Citazione MLA

Perrin,William F, e J.G.M Wursig,Bernd Thewissen. Encyclopedia of Marine Mammals. 2nd ed. Elsevier, 2009.