1. Parnell, M.; Sterling, H. F. (Elec. Commun. 43 [1968] 63/9; CA. 69 [1968] No. 71693).
2. Toshiba Corp. (Japan. Kokai Tokkyo Koho 58–14560 [1981/83] from C.A. 98 [1983] No. 226449).
3. NEC Corp. (Japan. Kokai Tokkyo Koho 59–191366 [1983/84] from CA. 102 [1985] No. 159109).
4. Nippondenso Co., Ltd. (Japan. Kokai Tokkyo Koho 59–228752 [1983/84] from CA. 103 [1985] No. 15586).
5. Hitachi Ltd. (Japan. Kokai Tokkyo Koho 58–143560 [1982/83] from CA. 99 [1983] No. 223641).