Citazione Stile APA (7a Edizione)

Fitter, R. (1967). The Penguin dictionary of british natural history. Penguin Books.

Citazione stile Chigago Style (17a edizione)

Fitter, Richard. The Penguin Dictionary of British Natural History. Londres: Penguin Books, 1967.

Citatione MLA (9a ed.)

Fitter, Richard. The Penguin Dictionary of British Natural History. Penguin Books, 1967.