APA (7th ed.) Zitazioa
(1990). The Europa world year book 1990: Vol. 1 part one international organizations, part two afghanistan-jordan. Europa Publications.
Chicago Style (17th ed.) Zitazioa
The Europa World Year Book 1990: Vol. 1 Part One International Organizations, Part Two Afghanistan-jordan. Bedford Square, New York: Europa Publications, 1990.
MLA (9th ed.) Zitazioa
The Europa World Year Book 1990: Vol. 1 Part One International Organizations, Part Two Afghanistan-jordan. Europa Publications, 1990.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.