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 E. Emery. On Purposeful Systems. Chicago: Aldine. Atherton, 1972.

MLA (9th ed.) Citation

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