Whitehead, A. N., & Russell, B. (1935). Principia mathematica. London: Cambridge University press.
Dyfyniad Arddull ChicagoWhitehead, Alfred North., và Bertrand Russell. Principia Mathematica. London: Cambridge University press, 1935.
Dyfyniad MLAWhitehead, Alfred North., và Bertrand Russell. Principia Mathematica. London: Cambridge University press, 1935.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.