APA (7th ed.) Citation

Henderson, J. V., & Poole, W. (1991). Principles of economics. Heath.

Chicago Style (17th ed.) Citation

Henderson, J. Vernon, and William Poole. Principles of Economics. Boston [etc.]: Heath, 1991.

MLA (9th ed.) Citation

Henderson, J. Vernon, and William Poole. Principles of Economics. Heath, 1991.