Engels, F. (1949). The Part played by labour in the transition from ape to man.
استشهاد بنمط شيكاغوEngels, Friedrich. The Part Played by Labour in the Transition from Ape to Man. Moscow, 1949.
MLA استشهادEngels, Friedrich. The Part Played by Labour in the Transition from Ape to Man. 1949.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.