Unstead, R. J. (1972). From Cavemen to Vikings (2. ed.). Black.
Cita Chicago Style (17a ed.)Unstead, R. J. From Cavemen to Vikings. 2. ed. London: Black, 1972.
Cita MLA (9a ed.)Unstead, R. J. From Cavemen to Vikings. 2. ed. Black, 1972.
Precaución: Estas citas no son 100% exactas.