APA (7th ed.) Citation

Swarth, H. S. (1920). The Subspecies of Branta Canadensis (Linnaeus). The Auk, 37(2), 268.

Chicago Style (17th ed.) Citation

Swarth, H. S. "The Subspecies of Branta Canadensis (Linnaeus)." The Auk 37, no. 2 (1920): 268.

MLA (9th ed.) Citation

Swarth, H. S. "The Subspecies of Branta Canadensis (Linnaeus)." The Auk, vol. 37, no. 2, 1920, p. 268.