1. T. King, Modern Morse code in Rehabilitation and Education: New Applications in Assistive Technology, Allyn & Bacon, Boston, 2000.
2. D. Bearden, Mobile Unit Promotes Training, Hiring Handicapped, Institute for Electronic and Electrical Engineering, July 1981, pp. 150–151.
3. Computer-terminal operating and communication aid for the severely handicapped;Lywood;Med. Biol. Eng.,1974
4. Morse-code controlled computer aid for the non-vocal quadriplegic;Shannon;Med. Instrumen.,1981
5. Communication devices for the non-vocal disabled;Thomas;Computer,1981