Brevetto di un porta mine. {{SamePatent|FR|363394}} {{AdditionTo|DE|176702}}
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Brevetto di un porta mine. {{AdditionTo|DE|176702}} {{SamePatent|FR|06524E}} {{SamePatent|DK|09918}} {{SamePatent|GB|190616715}} {{SamePatent|CH|37618}} {{SamePatent|AT|31185}} {{SamePatent|CA|104033}}