Percentage of Students Using Drugs During the Previous 30 Days: 1991-98. US Department of Education.
Cita Chicago (17th ed.)Percentage of Students Using Drugs During the Previous 30 Days: 1991-98. US Department of Education.
Cita MLA (8th ed.)Percentage of Students Using Drugs During the Previous 30 Days: 1991-98. US Department of Education.
Atenció: Aquestes cites poden no estar 100% correctes.