Principia mathematica,
by Alfred North Whitehead and Bertrand Russell.
APA Citation
Whitehead, A. North., Russell, B. (1959). Principia mathematica. 2d ed. Cambridge: The University press.
MLA Citation
Whitehead, Alfred North, 1861-1947, and Bertrand Russell. Principia Mathematica. 2d ed. Cambridge: The University press, 1959.
Warning: These citations may not always be complete (especially for serials).