TY  - RPRT
TI  - Letter: Speaking aid.
AU  - C G Evans
AU  - A Atkinson
PY  - 1974
DO  - 10.1016/s0140-6736(74)90990-8
UR  - https://pubmed.ncbi.nlm.nih.gov/4143055/
ID  - 4143055
ER  -