APA
Moore G. E. 1., . (1903). Principia ethica. Cambridge: Cambridge University press.
Chicago
Moore George Edward 1873, . 1903. Principia ethica. Cambridge: Cambridge University press.
Harvard
Moore G. E. 1., . (1903). Principia ethica. Cambridge: Cambridge University press.
MLA
Moore George Edward 1873, . Principia ethica. Cambridge: Cambridge University press. 1903.
