APA (7th ed.) Citation

Hardin, G., & Gillespie, E. L. (1949). Biology: Its human implications. Freeman.

Chicago Style (17th ed.) Citation

Hardin, Garrett, and Evan L. Gillespie. Biology: Its Human Implications. San Francisco: Freeman, 1949.

MLA (9th ed.) Citation

Hardin, Garrett, and Evan L. Gillespie. Biology: Its Human Implications. Freeman, 1949.