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US2206538A
(en)
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Telephone system
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US1914384A
(en)
|
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Telephone system
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SE125373C1
(Direct)
|
|
|
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US4245214A
(en)
|
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Switching matrix
|
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US1593387A
(en)
|
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Telephone-exchange system
|
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US3313888A
(en)
|
|
Split-switch crossbar trunking system
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US3558828A
(en)
|
|
Electronic scanners
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US3522387A
(en)
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Circuit arrangement to control a number of functional units having a central logic in common
|
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US3729593A
(en)
|
|
Path finding system
|
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US2837603A
(en)
|
|
Automatic telephone system
|
|
US2311800A
(en)
|
|
Communication system
|
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GB1120651A
(en)
|
|
Improvements in or relating to telecommunication exchange systems
|
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US1612014A
(en)
|
|
Recording mechanism
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|
US1533182A
(en)
|
|
Telephone-exchange system
|
|
DE2647376C2
(de)
|
|
Schaltungsanordnung für zentral gesteuerte Fernmeldevermittlungsanlagen mit einem Zentralsteuerwerk und Teilsteuerungen
|
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US1542977A
(en)
|
|
Telephone-exchange system
|
|
US2768240A
(en)
|
|
Crossbar-switch line-finder system
|
|
GB1181181A
(en)
|
|
Switching Network
|
|
US1567242A
(en)
|
|
Telephone-exchange system
|
|
US1648122A
(en)
|
|
Telephone-exchange system |
|
US2528269A
(en)
|
|
Selector switch control for automatic telephone systems
|
|
US1595084A
(en)
|
|
Telephone-exchange system
|
|
US1559244A
(en)
|
|
Telephone-exchange system
|
|
US2810018A
(en)
|
|
Automatic telephone systems
|
|
US2839611A
(en)
|
|
Pbx line-hunting system
|