United States Library of Congress Classification Division & Gale Research Company. (1950). Classification. Class B, part 1, B-BJ: Philosophy (2nd ed.). U. S. Government Printing Office.
Lua i Stíl Chicago (17ú heag.)United States Library of Congress Classification Division agus Gale Research Company. Classification. Class B, Part 1, B-BJ: Philosophy. 2nd ed. Washington: U. S. Government Printing Office, 1950.
Lua MLA (9ú heag.)United States Library of Congress Classification Division agus Gale Research Company. Classification. Class B, Part 1, B-BJ: Philosophy. 2nd ed. U. S. Government Printing Office, 1950.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.