Cohen, W. A. (1991). How to make it big as a consultant (2nd ed.). Amacom.
Dyfyniad Arddull ChicagoCohen, William A. How to Make It Big as a Consultant. 2nd ed. New York: Amacom, 1991.
Dyfyniad MLACohen, William A. How to Make It Big as a Consultant. 2nd ed. Amacom, 1991.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.