APA (7th ed.) Citation

Ackoff, R. L., & Emery, F. E. (1972). On purposeful systems. Aldine-Atherton.

Chicago Style (17th ed.) Citation

Ackoff, Russell Lincoln, and Frederick Edmund Emery. On Purposeful Systems. Chicago: Aldine-Atherton, 1972.

MLA (9th ed.) Citation

Ackoff, Russell Lincoln, and Frederick Edmund Emery. On Purposeful Systems. Aldine-Atherton, 1972.