Bello, I. (1998). Elementary algebra. Brooks/Cole Publishing Company.
Lua i Stíl Chicago (17ú heag.)Bello, Ignacio. Elementary Algebra. Pacific Grove: Brooks/Cole Publishing Company, 1998.
Lua MLA (9ú heag.)Bello, Ignacio. Elementary Algebra. Brooks/Cole Publishing Company, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.