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US3867582A
(en)
|
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Remote control for private automatic branch telephone exchange
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NO138525B
(no)
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Apparat for omdannelse av oksygen til ozon
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|
US3573389A
(en)
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|
Switching system with individual register control
|
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US3178516A
(en)
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Call forwarding arrangement
|
|
US3963875A
(en)
|
|
Universal answer arrangement for a PABX
|
|
US3555198A
(en)
|
|
Identifier to determine the class of service to which a subscriber is entitled
|
|
US3182134A
(en)
|
|
Circuit for interconnecting a number of calling lines
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|
US3544729A
(en)
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|
Switching system arrangement for terminating a call to a line other than a called line
|
|
US3137770A
(en)
|
|
Telephone call holding arrangement
|
|
US2496902A
(en)
|
|
Private automatic telephone system of the passing call type
|
|
PL66389B1
(ja)
|
|
|
|
US3705275A
(en)
|
|
Telephone trunk testing system
|
|
US3251949A
(en)
|
|
Intergroup transfer circuit
|
|
US2976368A
(en)
|
|
Incoming trunk circuit for in-dialing service
|
|
GB588563A
(en)
|
|
Improvements in or relating to telephone systems
|
|
US3472968A
(en)
|
|
Connecting device for waiting in automatic telephone plants
|
|
US3320367A
(en)
|
|
Telephone line circuit
|
|
US3014989A
(en)
|
|
Incoming telephone call pabx restrictive service
|
|
US2732442A
(en)
|
|
murray |
|
US2299513A
(en)
|
|
Telephone or like system
|
|
US3420968A
(en)
|
|
Service observing system
|
|
US3417204A
(en)
|
|
Telephone trunk circuit
|
|
US2899503A
(en)
|
|
Dial telephone system arranged for machine |
|
US3836723A
(en)
|
|
Answering system for pbxs
|
|
US3211838A
(en)
|
|
Traffic between private automatic branch telephone exchanges
|