APA (7th ed.) Citation

Ernst, C. H. (2003). Snakes of the United States and Canada. Smithsonian Books.

Chicago Style (17th ed.) Citation

Ernst, Carl H. Snakes of the United States and Canada. Washington, D.C. [u.a.]: Smithsonian Books, 2003.

MLA (9th ed.) Citation

Ernst, Carl H. Snakes of the United States and Canada. Smithsonian Books, 2003.