APA (7th ed.) Zitazioa
Gurney Gene. (1970). Fact Book: Of the countries of the world. Crown Publ. Inc..
Chicago Style (17th ed.) Zitazioa
Gurney Gene. Fact Book: Of the Countries of the World. New York: Crown Publ. Inc., 1970.
MLA (9th ed.) Zitazioa
Gurney Gene. Fact Book: Of the Countries of the World. Crown Publ. Inc., 1970.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.