"A/D and D/A Conversion System for A-Law Pulse Code Modulation" by A. Pele IBM Technical Disclosure Bulletin, vol. 18, No. 8, Jan. 1976, pp. 2686-2688. |
"Delta Modulation Coding With Nonuniform Adaptive Companding" by R. J. Hallett, et al., IBM Technical Disclosure Bulletin, vol. 22, No. 1, Jun. 1979, pp. 217-219. |
"Voice Response for Data Processing Equipment" by G. L. Crauwels et al., IBM Technical Disclosure Bulletin, vol. 24, No. 11B, Apr. 1982, pp. 5890-5895. |
"Overflow Control in Voice Coder" by C. Galand et al., IBM Technical Disclosure Bulletin, vol. 26, No. 10A, Mar. 1984, p. 5300. |
"Full Duplex Speakerphone" by M. A. Einkauf et al., IBM Technical Disclosure Bulletin, vol. 29, No. 12, May 1987, pp. 5599-5602. |
"Digital Speakerphones: Is Full-Duplex Possible" by Gary Kloesz, Business Communications, Jul. 13, 1987, pp. 36 & 40. |