R. S. Nickerson D. N. Kalikow K. N. Stevens A computer-based system of speech-training aids for the deaf: a progress report. 125-126 1974 AFIPS National Computer Conference http://doi.acm.org/10.1145/1500175.1500198 conf/afips/1974 db/conf/afips/ncc74.html#NickersonKS74