Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (9th ed.)

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