APA (7th ed.) Citation

Gemmill, P. F., & Blodgett, R. H. (1942). Economics: Principles and problems (Rev. ed.). Harper.

Chicago Style (17th ed.) Citation

Gemmill, Paul Fleming, and Ralph Hamilton Blodgett. Economics: Principles and Problems. Rev. ed. New York: Harper, 1942.

MLA (9th ed.) Citation

Gemmill, Paul Fleming, and Ralph Hamilton Blodgett. Economics: Principles and Problems. Rev. ed. Harper, 1942.