APA (7th ed.) Citation

Gemmill, P. F. (1948). Economics: Principles and problems (3rd ed. vol. 1 & 2.). Harper.

Chicago Style (17th ed.) Citation

Gemmill, Paul F. Economics: Principles and Problems. 3rd ed. vol. 1 & 2. New York: Harper, 1948.

MLA (9th ed.) Citation

Gemmill, Paul F. Economics: Principles and Problems. 3rd ed. vol. 1 & 2. Harper, 1948.