<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/schema/zthes-1.0.dtd">  <Zthes><term><termId>4958</termId><termName>OPERADORES LAPLACIANOS</termName><termType>PT</termType><termLanguage>es-ES</termLanguage><termVocabulary>TESAURO DE MATERIAS DE SERBIULA</termVocabulary>	<termStatus>active</termStatus>	<termApproval>approved</termApproval>	<termSortkey>OPERADORES LAPLACIANOS</termSortkey><termCreatedDate>OPERADORES LAPLACIANOS</termCreatedDate><termModifiedDate>2015-02-25 15:14:17</termModifiedDate><relation><relationType>BT</relationType><termId>4942</termId><termName>ECUACIONES DIFERENCIALES PARCIALES</termName><termType>PT</termType></relation></term>  </Zthes>