TY  - RPRT
TI  - A telephone multiline signaling system
AU  - Toole, P. C.
AU  - Belt, J. L.
AU  - Goodloe, R.
AU  - Leiniger, D. B.
PY  - 1979
UR  - https://ntrs.nasa.gov/citations/19790000030
ID  - 19790000030
ER  -