APA (7th ed.) Citation

Williams, S. (1987). An Introduction to International law (2nd.ed.). Butterworths.

Chicago Style (17th ed.) Citation

Williams, S.A. An Introduction to International Law. 2nd.ed. Toronto: Butterworths, 1987.

MLA (9th ed.) Citation

Williams, S.A. An Introduction to International Law. 2nd.ed. Butterworths, 1987.