Cita APA (7th ed.)

Knorr, K. E., & Verba, S. (1961). The international system: Theoretical essays. Princeton University.

Cita Chicago (17th ed.)

Knorr, Klaus E., i Sidney Verba. The International System: Theoretical Essays. Princeton: Princeton University, 1961.

Cita MLA (9th ed.)

Knorr, Klaus E., i Sidney Verba. The International System: Theoretical Essays. Princeton University, 1961.