Popkin, R. H., & Stroll, A. (1956). Philosophie made simple. Doubleday & Company.
Lua i Stíl Chicago (17ú heag.)Popkin, Richard H., agus Avrum Stroll. Philosophie Made Simple. Garden City [u.a.]: Doubleday & Company, 1956.
Lua MLA (8ú heag.)Popkin, Richard H., agus Avrum Stroll. Philosophie Made Simple. Doubleday & Company, 1956.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.