Gredler, G.R., A look at some important factors in assessing readiness for school . Journal of Learning Disabilities, 1978, 11, 25-31.
2.
Halderman, B., Phye, G.D., Learning disabilities and age at the time of school entrance: Some preliminary findings. Toronto: American Educational Research Association, 1978.
3.
Koch, D., Kindergarten entrance age as a factor in school progress in selected school districts in Camden County. Unpublished doctoral dissertation, Teachers College, Columbia University, 1968 .