Dyfyniad APA
Riggs, J. L., Bedworth, D. D., & Randhawa, S. U. (2009). Engineering economics (4th ed.). McGraw-Hill.
Dyfyniad Arddull Chicago
Riggs, James L., David D. Bedworth, and Sabah U. Randhawa. Engineering Economics. 4th ed. New York: McGraw-Hill, 2009.
Dyfyniad MLA
Riggs, James L., et al. Engineering Economics. 4th ed. McGraw-Hill, 2009.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.