Sunusi, H. C.; Soetjiningsih, C. H.; Kristijanto, A. I. Communication Ability and Verbal Communication Apprehension of Senior High School Adolescents With Intellectual Disability: Research Based on Picture Exchange Communication System (PECS) and Measure of Elementary Communication Apprehension (MECA). ANIMA Indonesian Psychol. J. 2019, 34, 163-174.