APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

Gemmill, Paul F., and Ralph H. Blodgett. Economics: Principles and Problems. Rev. ed. .. New York, London: Harper & brothers, 1942.

MLA (9th ed.) Citation

Gemmill, Paul F., and Ralph H. Blodgett. Economics: Principles and Problems. Rev. ed. .. Harper & brothers, 1942.