Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

Whitehead, Alfred North, i Bertrand Russell. Principia Mathematica to *56. Cambridge: Cambridge University Press, 1997.

Cita MLA (9th ed.)

Whitehead, Alfred North, i Bertrand Russell. Principia Mathematica to *56. Cambridge University Press, 1997.