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(en )
2000-02-29
Network-based call hold stand by
US4068101A
(en )
1978-01-10
Method and apparatus for the automatic communication of two telephone subscribers
US2909607A
(en )
1959-10-20
Automatic telephone system with automatic transfer
BE460754A
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )
US2815404A
(en )
1957-12-03
Connection for automatic ring signal
US2302587A
(en )
1942-11-17
Telephone trunking system
US1558872A
(en )
1925-10-27
Telephone system
CH198010A
(fr )
1938-05-31
Installation téléphonique à batterie centrale.
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(en )
1933-10-17
Telephone system
BE391837A
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )
US938039A
(en )
1909-10-26
Apparatus and system for measuring telephone service.
US1901179A
(en )
1933-03-14
Automatic telephone system
US1393946A
(en )
1921-10-18
Telephone-exchange system
US1722538A
(en )
1929-07-30
Automatic telephone system
US1502916A
(en )
1924-07-29
Automatic telephone system
SU88727A1
(ru )
1949-11-30
Схемы шнуровой пары декадно-шаговой автоматической телефонной станции
DK141799B
(da )
1980-06-16
Abonnentkobling til telekommunikationsanlæg.
BE341584A
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )
BE455605A
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )
BE514857A
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )
BE383771A
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )
CH94572A
(fr )
1922-05-01
Installation pour bureaux centraux téléphoniques automatiques.
PL39271B1
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )
1955-12-15
GB263210A
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )
BE349415A
(c_deeref_Disk_and_Scratch_Disk_Pools_and_Their_Defaults.html )