<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/schema/zthes-1.0.dtd">  <Zthes><term><termId>4523</termId><termName>Arcilla refractaria</termName><termType>PT</termType><termLanguage>es</termLanguage><termVocabulary>INDICES DE MATERIAS</termVocabulary>	<termStatus>active</termStatus>	<termApproval>approved</termApproval>	<termSortkey>Arcilla refractaria</termSortkey><termNote label="Source"><![CDATA[ 552.52 ]]></termNote><termCreatedDate>Arcilla refractaria</termCreatedDate><relation><relationType>BT</relationType><termId>4518</termId><termName>Área 12. Petrografía y Petrología</termName><termType>PT</termType></relation></term>  </Zthes>