https://animorepository.dlsu.edu.ph/etd_bachelors/9245/
"A digital PABX with teleconferencing capability" by Concepcion Leilani V. Carandang, Jaime L....
By Concepcion Leilani V. Carandang, Jaime L. Gilbuela II, Ermanie L. Mendiola, et al., Published on 01/01/91
digital pabxteleconferencingcapabilityconcepcionleilani