TY - GEN AU - Idris, Maj Qazi Muhammad (TE-19) TI - Telephone ringer convertor : Maj Qazi Muhammad Idris, Capt Syed Muhammad Kaleem and Capt Ashraf Masood U1 - 621.382 CY - Rawalpindi PB - MCS KW - UG Projects KW - TE-19 ER -