APA (7th ed.) Citation

Nielsen, K. (1990). Ethics without God (Rev. ed.). Prometheus Books.

Chicago Style (17th ed.) Citation

Nielsen, Kai. Ethics Without God. Rev. ed. Amherst, N.Y.: Prometheus Books, 1990.

MLA (9th ed.) Citation

Nielsen, Kai. Ethics Without God. Rev. ed. Prometheus Books, 1990.