Astuty, A., Rustono, R., Su’udiE. and Mulyani, M. (2017) “THE WORD, PHRASE, AND SENTENCE PRODUCTIVITY, AND THE AVERAGE LENGTH OF UTTERANCES AMONG CHILDREN WITH MILD MENTAL RETARDATION”, The Journal of Educational Development, 5(1), pp. 128-135. doi: 10.15294/jed.v5i1.14305.