APA

Boehm R.G, Armstrong D.C & Hankis F.P. (2003). Geography. The World and Its People. New York: Mc Graw Hill.

Chicago

Boehm R.G, Armstrong D.C and Hankis F.P. 2003. Geography. The World and Its People. New York: Mc Graw Hill.

Harvard

Boehm R.G, Armstrong D.C and Hankis F.P. (2003). Geography. The World and Its People. New York: Mc Graw Hill.

MLA

Boehm R.G, Armstrong D.C and Hankis F.P. Geography. The World and Its People. New York: Mc Graw Hill. 2003.