Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

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

Citatione MLA (8a ed.)

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