APA (7th ed.) Citation

HarperCollins, Ekelund, R., & Tollison, R. (1991). Economics (3rd.). HarperCollins.

Chicago Style (17th ed.) Citation

HarperCollins, R. Ekelund, and R. Tollison. Economics. 3rd. New York: HarperCollins, 1991.

MLA (8th ed.) Citation

HarperCollins, et al. Economics. 3rd. HarperCollins, 1991.

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