<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>1759</termId><termName>Metales alcalinos</termName><termType>PT</termType><termCreatedDate>2014-09-15 19:35:37</termCreatedDate><relation><relationType>BT</relationType><termId>1758</termId><termName>Metales ligeros</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>1762</termId><termName>Cesio</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>1760</termId><termName>Litio</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>1764</termId><termName>Potasio</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>1761</termId><termName>Rubidio</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>1763</termId><termName>Sodio</termName><termType>PT</termType></relation></term>  </Zthes>