APA (7th ed.) Citation

Emmons, W. H. (1940). The principles of economic geology (2. edition, 4. impression.). McGraw-Hill.

Chicago Style (17th ed.) Citation

Emmons, William H. The Principles of Economic Geology. 2. edition, 4. impression. New York ; London: McGraw-Hill, 1940.

MLA (9th ed.) Citation

Emmons, William H. The Principles of Economic Geology. 2. edition, 4. impression. McGraw-Hill, 1940.