<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31449686</termId><termName>semi-rigid airships</termName><termType>PT</termType><termNote><![CDATA[ Airships constructed with partial frameworks consisting of rigid, or partially flexible keel frames along the long axis under an aerodynamic hull envelope. ]]></termNote><termCreatedDate>2026-03-30 21:01:05</termCreatedDate><relation><relationType>UF</relationType><termId>31449687</termId><termName>airships, semi-rigid</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31449688</termId><termName>semi-rigid airship</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31449689</termId><termName>semirigid airships</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31426114</termId><termName>airships</termName><termType>PT</termType></relation></term>  </Zthes>