Dyfyniad APA

Trewartha, . G. T., Robinson, A. H., & Hammond, E. H. (1967). Elements of Geography (5th ed.). McGraw-Hill.

Dyfyniad Arddull Chicago

Trewartha, Glenn T., Arthur H. Robinson, and Edwin H. Hammond. Elements of Geography. 5th ed. New York: McGraw-Hill, 1967.

Dyfyniad MLA

Trewartha, Glenn T., et al. Elements of Geography. 5th ed. McGraw-Hill, 1967.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.