APA Edition Citation

Hardin, G. (1968). 39 steps to biology. W.H freeman.

Chicago Edition Citation

Hardin, G. 39 Steps to Biology. Londan: W.H freeman, 1968.

MLA Edition Citation

Hardin, G. 39 Steps to Biology. W.H freeman, 1968.

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