Schiller, F. C. S. (1968). Riddles of the sphinx: A study in the philosophy of humanism. Greenwood Press.
Dyfyniad Arddull ChicagoSchiller, F. C. S. Riddles of the Sphinx: A Study in the Philosophy of Humanism. New York: Greenwood Press, 1968.
Dyfyniad MLASchiller, F. C. S. Riddles of the Sphinx: A Study in the Philosophy of Humanism. Greenwood Press, 1968.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.