Cita APA (7a ed.)

Wolfke, K. (1993). Custom in present international law (2nd rev. ed.). Martinus Nijhoff.

Cita Chicago Style (17a ed.)

Wolfke, Karol. Custom in Present International Law. 2nd rev. ed. Dordrecht [etc.]: Martinus Nijhoff, 1993.

Cita MLA (9a ed.)

Wolfke, Karol. Custom in Present International Law. 2nd rev. ed. Martinus Nijhoff, 1993.