Speech immunity voice frequency signalling system

作者: Herter Eberhard

DOI:

关键词:

摘要:

参考文章(5)
Deakin Gerald, Electrical signaling system ,(1944)
Leo Schenker, Alessandro Busala, Fred West, Subscriber call transmitting system ,(1957)
Nilsson Nils Emil, Rodnert Gustav Oscar, Bjork John Carl Harold, Connecting device for private automatic branch exchanges ,(1957)