5.奴隶的平均价格:Ralph A. Austen, “The Trans-Saharan Slave Trade: A Tentative Census.” The Uncommon Market: Essays in the Economic History of the Atlantic Slave Trade, ed. Henry A. Gemery and Jan S. Hogendorn (1979): 23-73,其中31页提及努比亚在奴隶贸易中的付出,44—45页提及伊斯兰世界的奴隶劳动,45页提到了津芝人叛乱,52—55页提到了军事奴隶,70页上有奴隶价格数据。
6.第一批反对奴隶制的废奴主义者:David Brion Davis, The Problem of Slavery in Western Culture (1967): 484-493.