Prowoto, J., Sastra, G. and Yanis, A. 2019. Phonological Disorders of Children with Down Syndrome Based on the Level of Intelligence: A Case Study. OKARA: Jurnal Bahasa dan Sastra. 13, 1 (May 2019), 81-92. DOI:https://doi.org/10.19105/ojbs.v13i1.2276.