Astuty, A., R. Rustono, Su’udiE., and M. Mulyani. “THE WORD, PHRASE, AND SENTENCE PRODUCTIVITY, AND THE AVERAGE LENGTH OF UTTERANCES AMONG CHILDREN WITH MILD MENTAL RETARDATION”. The Journal of Educational Development, Vol. 5, no. 1, May 2017, pp. 128-35, doi:10.15294/jed.v5i1.14305.