References
- Asha A D. Hoc Committee of Communication Processes and Non Speaking Persons Non-speech communication: A position paper. American Speech and Hearing Association 1980; 22: 267–272
- Enderby P., Philipp R. Speech and language handicap: towards knowing the size of the problem. British Journal of Disorders of Communication 1986; 21: 151–165
- Matas J. A., Mathy-Laiko P., Beukelman D. R., Lecresely K. Identifying the nonspeaking population: A demographic study. Augmentative and Alternative Communication 1985; 1: 17–31
- Rowley C, Stowe J., Bryant J., Chamberlain M. Communication aids provision 1983–1986. British Journal of Disorders of Communication 1988; 23: 1–11
- Quirk R. Speech Therapy Services. HMSO, London 1972