Denham, C., & Lieberman, A. (1980). Time to learn. U.S. Department of education.
Lua i Stíl Chicago (17ú heag.)Denham, Carolyn, agus Ann Lieberman. Time to Learn. California: U.S. Department of education, 1980.
Lua MLA (9ú heag.)Denham, Carolyn, agus Ann Lieberman. Time to Learn. U.S. Department of education, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.