APA (7th ed.) Citation

Smith, G. M. (1950). The fresh-water algae of the United States (2a. ed.). McGraw-Hill.

Chicago Style (17th ed.) Citation

Smith, Gilbert Morgan. The Fresh-water Algae of the United States. 2a. ed. Nueva York: McGraw-Hill, 1950.

MLA (9th ed.) Citation

Smith, Gilbert Morgan. The Fresh-water Algae of the United States. 2a. ed. McGraw-Hill, 1950.