APA (7th ed.) Citation

DeGARMO, E. P., SULLIVAN, W. G., & BONTADELLI, J. A. (1989). Engineering economy. -- 8th ed. Macmillan.

Chicago Style (17th ed.) Citation

DeGARMO, E. Paul, William G. SULLIVAN, and James A. BONTADELLI. Engineering Economy. -- 8th Ed. New York: Macmillan, 1989.

MLA (9th ed.) Citation

DeGARMO, E. Paul, et al. Engineering Economy. -- 8th Ed. Macmillan, 1989.