Nelson, E. (1930). Wild animals of North America: Intimate study of big and little creatures of the mammals kingdom. The National Geographic Society.
Chicago-referens (17:e uppl.)Nelson, E.W. Wild Animals of North America: Intimate Study of Big and Little Creatures of the Mammals Kingdom. Washington: The National Geographic Society, 1930.
MLA-referens (9:e uppl.)Nelson, E.W. Wild Animals of North America: Intimate Study of Big and Little Creatures of the Mammals Kingdom. The National Geographic Society, 1930.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.