Kena, G., Hussar, W., McFarland, J., de Brey, C., Musu-Gillette, L., Wang, X. et al. (2016). The Condition of Education 2016 (NCES 2016-144). (Rapport no. NCES 2016-144). Washington, DC.. U.S. Department of Education, National Center for Education Statistics. http://nces.ed.gov/pubs2016/2016144.pdf