Παραπομπή APA

Engels, F. (1949). The Part played by labour in the transition from ape to man.

Παραπομπή Chicago Style

Engels, Friedrich. The Part Played by Labour in the Transition from Ape to Man. Moscow, 1949.

Παραπομπή MLA

Engels, Friedrich. The Part Played by Labour in the Transition from Ape to Man. 1949.