Durkin, M.S., H. Schneider, V.S. Pathania, K.B. Nelson, G.C. Solarsh, N. Bellows, R.M. Scheffler, and K.J. Hofman. “Learning and Developmental Disabilities.” Disease Control Priorities in Developing Countries, 2nd Edition, Chapter 49. Jamison, D.T., et al (eds.) World Bank and Oxford University Press (Apr. 2006): 933-51.