APA (7th ed.) Citation

Froman, L. A. (1940). Principles of economics (Rev. ed.). Irwin.

Chicago Style (17th ed.) Citation

Froman, Lewis A. Principles of Economics. Rev. ed. Chicago, Ill: Irwin, 1940.

MLA (9th ed.) Citation

Froman, Lewis A. Principles of Economics. Rev. ed. Irwin, 1940.