Williams, R. J. (1979). Free and unequal: The biological basis of individual liberty. Liberty Press.
芝加哥风格引文Williams, Roger J. Free and Unequal: The Biological Basis of Individual Liberty. Indianapolis: Liberty Press, 1979.
MLA引文Williams, Roger J. Free and Unequal: The Biological Basis of Individual Liberty. Liberty Press, 1979.
警告：这些引文格式不一定是100％准确.