Trewartha, . G. T., Robinson, A. H., & Hammond, E. H. (1967). Elements of Geography (5th ed.). McGraw-Hill.
Chicago Style (17th ed.) ZitazioaTrewartha, Glenn T., Arthur H. Robinson, eta Edwin H. Hammond. Elements of Geography. 5th ed. New York: McGraw-Hill, 1967.
MLA (9th ed.) ZitazioaTrewartha, Glenn T., et al. Elements of Geography. 5th ed. McGraw-Hill, 1967.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.