(2000). Percentage of Students Using Drugs During the Previous 30 Days: 1991-98. U.S. Department of Education.
Lua i Stíl Chicago (17ú heag.)Percentage of Students Using Drugs During the Previous 30 Days: 1991-98. U.S. Department of Education, 2000.
Lua MLA (9ú heag.)Percentage of Students Using Drugs During the Previous 30 Days: 1991-98. U.S. Department of Education, 2000.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.