—x 1957 Sondhi2) 1) 7 ± 1970 LSI ATT Duttweiller3) T, Y 'c De, ATT, LSI & HE b, t NTT tt...
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—x 1957 Sondhi2) 1) 7 ± 1970 LSI ATT Duttweiller3) T, Y 'c De, ATT, LSI & HE b, t NTT tt NTT "Recent Techniques of Circuit and Acoustic Echo Control for Telephony" by Shoji Shimada
