GB191203497A
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Improvements in and relating to Switching Apparatus for Telephone Exchange Systems.
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GB191107611A
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Improvements in and relating to Telephone Exchange Systems.
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GB190918950A
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Improvements in and relating to Telephone Exchange System.
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GB190924615A
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Improvements in and relating to Electrical Selecting Systems, particularly applicable to Telephone Exchange Systems.
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GB190924616A
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Improvements in and relating to a Telephone Exchange System.
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GB190827139A
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Improvements in and relating to a Telephone Exchange System.
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GB190628091A
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Improvements in or relating to Telephone Exchange Systems.
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GB190302598A
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Improvements in and relating to Electrical Transmission Systems.
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