APA Edition Citation

Gregory, P. R., & Ruffin, R. J. (1990). Principes of economics. Sccott, Freshman and company.

Chicago Edition Citation

Gregory, Paul R., and Roy J. Ruffin. Principes of Economics. London: Sccott, Freshman and company, 1990.

MLA Edition Citation

Gregory, Paul R., and Roy J. Ruffin. Principes of Economics. Sccott, Freshman and company, 1990.

Warning: These citations may not always be 100% accurate.