Cita APA (7th ed.)

Unstead, J. F. (1929). World geography and world problems (2nd impression, rev.). Sidgwick & Jackson.

Cita Chicago (17th ed.)

Unstead, J. F. World Geography and World Problems. 2nd impression, rev. London: Sidgwick & Jackson, 1929.

Cita MLA (8th ed.)

Unstead, J. F. World Geography and World Problems. 2nd impression, rev. Sidgwick & Jackson, 1929.