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CA1209289A
(en)
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Charging process for selling information by telephone
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US2782257A
(en)
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Automatic telephone system
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US1972326A
(en)
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System for automatically detecting errors in telegraph reception
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GB516348A
(en)
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Improvements in or relating to automatic or semi-automatic telephone systems
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USRE23388E
(en)
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Line identification circuit for |
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GB550235A
(en)
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Improvements in telephone systems
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US2645764A
(en)
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Intelligence exchange system
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SE182717C1
(enExample)
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US4085293A
(en)
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Traffic usage recorder
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US2997545A
(en)
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Automatic telecommunication exchanges
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US4250354A
(en)
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Telephone day count traffic observing and data accumulating equipment
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NO138909B
(no)
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Fremgangsmaate til demetallisering av en hydrocarbonolje i naervaer av hydrogen og en katalysator av vanadium og nikkel paa siliciumoxydbaerer
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US2272311A
(en)
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Testing and indicating apparatus
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US2730568A
(en)
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Starting next idle register
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US3169169A
(en)
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|
Traffic observation system
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US3271522A
(en)
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|
Circuit arrangement for determining the call numbers of party line subscribers
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US2645420A
(en)
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Calculator equipment working with teleprinter
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US3794783A
(en)
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|
Telephone-system monitoring and recordal apparatus using ordinary paper
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US2863958A
(en)
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|
Telephone identification test system
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US3256392A
(en)
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|
Circuit arrangement for determining party line subscriber numbers
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US2651680A
(en)
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Dual-use register sender
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US1611445A
(en)
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|
Trouble-indicating system
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|
US2570239A
(en)
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|
Time zone telephone metering system
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US2076672A
(en)
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|
Stock quotation system
|
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US1615971A
(en)
|
|
Telephone-exchange system
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