Olafson, F. A. (1967). Principles and persons: An ethical interpretation of existentialism. Johns Hopkins Press.
Lua i Stíl Chicago (17ú heag.)Olafson, Frederick A. Principles and Persons: An Ethical Interpretation of Existentialism. Baltimore: Johns Hopkins Press, 1967.
Lua MLA (9ú heag.)Olafson, Frederick A. Principles and Persons: An Ethical Interpretation of Existentialism. Johns Hopkins Press, 1967.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.