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US2169910A
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Sound recording system
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GB464971A
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Improvements in or relating to light-sensitive cell systems for the scanning of sound tracks
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GB476318A
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Improvements in or relating to the reproduction of sound records
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GB473268A
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Improvements in or relating to sound-film reproducing apparatus
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GB469385A
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Improvements in or relating to sound-film reproducing apparatus
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GB191327449A
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Arrangement for Automatically Controlling the Passage of a Heating Medium in Radiators of Central Heating Installations.
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GB191316186A
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Improvements in or relating to Heat Radiators.
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DE348015C
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Drive device for gas analysis apparatus, air pyrometers and other measuring devices acting through gas or air displacement
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