Lankford, F. G. (1975). Essential mathematics (3ª ed.). Harcourt Brace Jovanovich.
Lua i Stíl Chicago (17ú heag.)Lankford, Francis G. Essential Mathematics. 3ª ed. Harcourt Brace Jovanovich, 1975.
Lua MLA (9ú heag.)Lankford, Francis G. Essential Mathematics. 3ª ed. Harcourt Brace Jovanovich, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.