Williams, S. (1987). An Introduction to International law (2nd.ed.). Butterworths.
芝加哥风格引文Williams, S.A. An Introduction to International Law. 2nd.ed. Toronto: Butterworths, 1987.
MLA引文Williams, S.A. An Introduction to International Law. 2nd.ed. Butterworths, 1987.
警告：这些引文格式不一定是100％准确.