Witter, G. E. (1964). Mathematics: The study of axiom systems. Blaisdell Publishing.
Lua i Stíl Chicago (17ú heag.)Witter, George E. Mathematics: The Study of Axiom Systems. New York: Blaisdell Publishing, 1964.
Lua MLA (9ú heag.)Witter, George E. Mathematics: The Study of Axiom Systems. Blaisdell Publishing, 1964.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.