APA (7th ed.) Citation

Ridgley, D. C., & Ekblaw, S. E. (1938). Influence of geography on our economic life. The Gregg publishing company.

Chicago Style (17th ed.) Citation

Ridgley, Douglas Clay, and Sidney Everette Ekblaw. Influence of Geography on Our Economic Life. New York, Chicago [etc.]: The Gregg publishing company, 1938.

MLA (9th ed.) Citation

Ridgley, Douglas Clay, and Sidney Everette Ekblaw. Influence of Geography on Our Economic Life. The Gregg publishing company, 1938.