Carnegie Council on Adolescent Development
. (1989). Turning points: Preparing American youth for the 21st century. New York: Carnegie Corporation.
2.
Oakes, J.
(1985). Keeping track: How schools structure inequality. New Haven, CT: Yale University Press.
3.
Wigfield, A.
, & Eccles, J. S. (1994). Middle grades schooling and early adolescent development: An introduction. Journal of Early Adolescence, 14, 102-106.