APA (7th ed.) Zitazioa

Engels, F. (1976). Frederick Engels: A biography. Progress Pub.

Chicago Style (17th ed.) Zitazioa

Engels, Frederick. Frederick Engels: A Biography. Moscow: Progress Pub, 1976.

MLA (9th ed.) Zitazioa

Engels, Frederick. Frederick Engels: A Biography. Progress Pub, 1976.