Citazione Stile APA (7a Edizione)

De Blij, H. J., Muller, P. O., & Palka, E. J. (2007). The world today: Concepts and regions in geography (3. ed.). Wiley.

Citazione stile Chigago Style (17a edizione)

De Blij, Harm J., Peter O. Muller, e Eugene J. Palka. The World Today: Concepts and Regions in Geography. 3. ed. Hoboken, N.J: Wiley, 2007.

Citatione MLA (9a ed.)

De Blij, Harm J., et al. The World Today: Concepts and Regions in Geography. 3. ed. Wiley, 2007.