APA (7th ed.) Citation

(1968). 39 steps to biology. W. H. Freeman and company.

Chicago Style (17th ed.) Citation

39 Steps to Biology. San Fransisco London: W. H. Freeman and company, 1968.

MLA (8th ed.) Citation

39 Steps to Biology. W. H. Freeman and company, 1968.

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