APA (7th ed.) Citation

Whitehead, A. N., & Russell, B. (1997). Principia mathematica: To 56. Cambridge University Press.

Chicago Style (17th ed.) Citation

Whitehead, Alfred North, and Bertrand Russell. Principia Mathematica: To 56. Cambridge: Cambridge University Press, 1997.

MLA (8th ed.) Citation

Whitehead, Alfred North, and Bertrand Russell. Principia Mathematica: To 56. Cambridge University Press, 1997.