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	mads.xsd"><authority><topic authority="http://www.serbi.ula.ve/tematres/vocab/">PERFORACIÓN DE POZOS PETROLEROS</topic></authority><related type="narrower"><topic>CEMENTACION DE POZOS PETROLEROS</topic></related><related type="narrower"><topic>LODOS DE PERFORACIÓN</topic></related><related type="narrower"><topic>PERFORACIÓN HORIZONTAL DE POZOS PETROLEROS</topic></related><variant type="other"><topic>Pozos petroleros--Perforación</topic></variant><variant type="other"><topic>Pozos petrolíferos--Perforación</topic></variant></mads>