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GB413904A
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Improvements in machines for moulding pipes or pipe coatings of concrete and the like
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US1954902A
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Manufacture of pipes or hollow ware of fibrous cement mortar or the like
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GB396572A
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Method of manufacture of tubes, posts or other hollow ware
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GB382290A
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Method of manufacture of tubes, posts or other hollow ware
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GB333266A
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Improved method of production of tubes, posts and other hollow ware of concrete material either reinforced or not
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GB259665A
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Improvements in and relating to tubes and the like
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GB238304A
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Improvements in and relating to the manufacture of tubular hollow ware and the like
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