OPPENHEIM, F. E. (1968). Moral principles in political philosophy. Random House.
芝加哥风格引文OPPENHEIM, Felix E. Moral Principles in Political Philosophy. New York: Random House, 1968.
MLA引文OPPENHEIM, Felix E. Moral Principles in Political Philosophy. Random House, 1968.
警告：这些引文格式不一定是100％准确.