United States. Office of Educational Research and Improvement & National Center for Education Statistics. (1990). Key statistics on public elementary and secondary education reported by state and by regional, locale, and wealth clusters. U.S. Dept. of Education, Office of Educational Research and Improvement.
Citazione stile Chigago Style (17a edizione)United States. Office of Educational Research and Improvement e National Center for Education Statistics. Key Statistics on Public Elementary and Secondary Education Reported by State and by Regional, Locale, and Wealth Clusters. Washington, D.C.: U.S. Dept. of Education, Office of Educational Research and Improvement, 1990.
Citatione MLA (8a ed.)United States. Office of Educational Research and Improvement e National Center for Education Statistics. Key Statistics on Public Elementary and Secondary Education Reported by State and by Regional, Locale, and Wealth Clusters. U.S. Dept. of Education, Office of Educational Research and Improvement, 1990.