Chutiwan Kaewsai Learning performance of mentally retarded children by using symbols in augmentative and alternative communication system. Thesis (M.Sc. (Communication Disorders))--Mahidol University, 2004. Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/105798
Title
Learning performance of mentally retarded children by using symbols in augmentative and alternative communication system
