<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31465787</termId><termName>quartz clocks</termName><termType>PT</termType><termNote><![CDATA[ Extremely accurate electronic clocks using the natural frequency of vibrations of quartz crystals to regulate the clock's movement. ]]></termNote><termCreatedDate>2026-03-30 21:05:22</termCreatedDate><relation><relationType>UF</relationType><termId>31465788</termId><termName>clocks, quartz</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31465789</termId><termName>quartz clock</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31465790</termId><termName>quartz-crystal clocks</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31450309</termId><termName>electronic clocks</termName><termType>PT</termType></relation></term>  </Zthes>