1. Beukelman, D. R. & Mirenda, P. (1998). Augmentative and alter-native communication: Management of severe communication disorders in children and adults (2nd ed.). Baltimore: Paul H. Brookes.
2. Early intervention for childrenʼs reading problems
3. Bloom, Y. (1990). Object symbols: A communication option. Syd-ney: North Rocks Press.
4. The Picture Exchange Communication System