Number and Percent of Mentally Retarded Students in Public School Classes

Grant W. V. & Lind C. G. (1974). Digest of Educational Statistics, 1973 Edition. U.S. Department of Health, Education, & Welfare, Publication No. (OE) 74-11103.

National Association for Retarded Citizens. (1971). Educational Services for Mentally Retarded Students in United States. Operational Research Report. Arlington, Tx.: NARC.