APA aipamena

William L Langer. (1968). An encyclopedia of world history. Boston, Massachusetts: Houghton Mifflin.

Chicago Style aipamena

William L Langer. An Encyclopedia of World History. Boston, Massachusetts: Houghton Mifflin, 1968.

MLA aipamena

William L Langer. An Encyclopedia of World History. Boston, Massachusetts: Houghton Mifflin, 1968.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.