Michael Tadman, "The Demographic Cost of Sugar: Debats on Slave Societies and Natural Increase in the Americas", The American Historical Review desembre de 2000 105:5 online(anglès)
American Civil War Census Data This source derived numbers for "% of Families Owning Slaves" by assuming only one slaveholder per family, a presumption with evidence only to the contrary. The summary numbers also include 17 slaves and 8 slaveowners counted by census-takers in Nebraska and Kansas, where slavery was illegal.
