<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31320319</termId><termName>oxalic acid</termName><termType>PT</termType><termNote><![CDATA[ Refers to a strong organic acid derived from sorrel and other plants. A crystalline powder, oxalic acid lends itself to many commercial applications, principally as a bleaching agent and as a reducing agent to remove tarnish, rust and ink stains. In art manufacture and conservation, further uses include removal of paint and varnish, and cleaning of encrustations from sculptures and paintings. ]]></termNote><termCreatedDate>2026-03-30 20:26:20</termCreatedDate><relation><relationType>UF</relationType><termId>31320320</termId><termName>acid, oxalic</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31306060</termId><termName>acid</termName><termType>PT</termType></relation></term>  </Zthes>