Drescher, S., & Engerman, S. L. (1998). Historical guide to World Slavery. Oxford University.
Dyfyniad Arddull ChicagoDrescher, Seymour, and Slanley L. Engerman. Historical Guide to World Slavery. New York: Oxford University, 1998.
Dyfyniad MLADrescher, Seymour, and Slanley L. Engerman. Historical Guide to World Slavery. Oxford University, 1998.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.