National Center for Education Statistics. (1999). Education statistics quarterly. National Center for Education Statistics, Office of Educational Research and Improvement, U.S. Dept. of Education.

National Center for Education Statistics. Education Statistics Quarterly. Washington, DC: National Center for Education Statistics, Office of Educational Research and Improvement, U.S. Dept. of Education, 1999.

National Center for Education Statistics. Education Statistics Quarterly. National Center for Education Statistics, Office of Educational Research and Improvement, U.S. Dept. of Education, 1999.