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mads.xsd"><authority><topic authority="http://roble.intecca.uned.es/tematres/lem/">Tubos electrónicos</topic></authority><related type="narrower"><topic>Diodos</topic></related><related type="other"><topic>Electrónica-Equipos</topic></related><related type="other"><topic>Amplificadores de tubos de vacío</topic></related><related type="other"><topic>Circuitos electrónicos</topic></related><variant type="other"><topic>Tubos de vacio</topic></variant><variant type="other"><topic>Tubos de radio</topic></variant><variant type="other"><topic>Válvulas electrónicas</topic></variant><variant type="other"><topic>Válvulas electricas</topic></variant></mads>