Russell, Bertrand (July 1908). “Mathematical logic as based on the theory of types”. 《American Journal of Mathematics》 30 (3): 222–262. doi:10.2307/2369948. JSTOR2369948.
Russell, Bertrand (July 1908). “Mathematical logic as based on the theory of types”. 《American Journal of Mathematics》 30 (3): 222–262. doi:10.2307/2369948. JSTOR2369948.