APA (7th ed.) Zitazioa
Okey, R. (1991). Eastern Europe 1740-1985: Feudalism to communism (2nd ed.). Routledge.
Chicago Style (17th ed.) Zitazioa
Okey, Robin. Eastern Europe 1740-1985: Feudalism to Communism. 2nd ed. London: Routledge, 1991.
MLA (9th ed.) Zitazioa
Okey, Robin. Eastern Europe 1740-1985: Feudalism to Communism. 2nd ed. Routledge, 1991.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.