APA (7th ed.) Citation

Whitney, L. F., & Hahnel, P. (1955). All about guppies.

Chicago Style (17th ed.) Citation

Whitney, Leon F., and Paul Hahnel. All About Guppies. 1955.

MLA (9th ed.) Citation

Whitney, Leon F., and Paul Hahnel. All About Guppies. 1955.

Warning: These citations may not always be 100% accurate.