Nash, G. B. (1991). Freedom by degrees: Emancipation in Pennsylvania and its aftermath. Oxford University Press.
芝加哥风格引文Nash, Gary B. Freedom by Degrees: Emancipation in Pennsylvania and Its Aftermath. New York: Oxford University Press, 1991.
MLA引文Nash, Gary B. Freedom by Degrees: Emancipation in Pennsylvania and Its Aftermath. Oxford University Press, 1991.
警告：这些引文格式不一定是100％准确.