APA (7th ed.) Citation

Whitbeck, R. H., Williams, F. E., & Chrsitians, W. F. (1940). Economic geography of south America. McGraw-Hill.

Chicago Style (17th ed.) Citation

Whitbeck, R. H., Frank E. Williams, and W. F. Chrsitians. Economic Geography of South America. New York: McGraw-Hill, 1940.

MLA (9th ed.) Citation

Whitbeck, R. H., et al. Economic Geography of South America. McGraw-Hill, 1940.

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