TREWARTHA, G. T., ROBINSON, A. H., & HAMMOND, E. H. (1967). Elements of geography: Physical and culture.-- ed.5. McGraw-Hill Book co.
Lua i Stíl Chicago (17ú heag.)TREWARTHA, Glenn T., Arthur H. ROBINSON, agus Edwin H. HAMMOND. Elements of Geography: Physical and Culture.-- Ed.5. New York: McGraw-Hill Book co, 1967.
Lua MLA (9ú heag.)TREWARTHA, Glenn T., et al. Elements of Geography: Physical and Culture.-- Ed.5. McGraw-Hill Book co, 1967.
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