Cita APA (7a ed.)

Whitehead, A. N. (1927). Principia mathematica: To 56. C.U.Pr.

Cita Chicago Style (17a ed.)

Whitehead, Alfred North. Principia Mathematica: To 56. Cambridge: C.U.Pr, 1927.

Cita MLA (9a ed.)

Whitehead, Alfred North. Principia Mathematica: To 56. C.U.Pr, 1927.