1U.S. Department of Education, National Center for Education Statistics, The Condition of Education 2003,NCES 2003-067, U.S. Government Printing Office, 2003, http://nees.ed.gov/programs/ccm/2OO3/pdf/05_2003.pdfi.
2Thomas D. Snyder and Charlene M. Hoffman: Digest of Education Statistics, 2001, Education Statistic Quarterly, Spring 2002, published by National Center for Education Statistics.
3U.S. Department of Education. National Center for Education Statistics, Education Statistics Quarte Jcly, Vol.3, Issue 2, Summer 2001, p.10. NCES 2001-605.
4U.S. Department of Education, National Center for Education Statistics, The condition of education 2002, PI21, http://nces.ed.gov/pubs2003/quartedy/fall/6_1.asp.
5U.S. Department of Education, National Center for Education Statistics, Education Statistics Quarterly, Vol.3, Issue 2, Summer 2001, p.11. NCES 2001-6052.