APA (7th ed.) Zitazioa
Spellman, F. R. (2009). Geography for nongeographers. Government Institutes.
Chicago Style (17th ed.) Zitazioa
Spellman, Frank R. Geography for Nongeographers. Lanham: Government Institutes, 2009.
MLA (9th ed.) Zitazioa
Spellman, Frank R. Geography for Nongeographers. Government Institutes, 2009.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.