Cita APA (7th ed.)

De Blij, H. J. (1967). Systematic political geography. Wiley.

Cita Chicago (17th ed.)

De Blij, Harm J. Systematic Political Geography. New York: Wiley, 1967.

Cita MLA (9th ed.)

De Blij, Harm J. Systematic Political Geography. Wiley, 1967.