<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/schema/zthes-1.0.dtd">  <Zthes><term><termId>54</termId><termName>Observational unit</termName><termType>TT</termType><termLanguage>en-EN</termLanguage><termVocabulary>SYMSITES</termVocabulary>	<termStatus>active</termStatus>	<termApproval>approved</termApproval>	<termSortkey>Observational unit</termSortkey><termNote label="Scope"><![CDATA[ <p>SYMSITES k-SDSS</p> ]]></termNote><termNote label="Definition"><![CDATA[ <p>The unit upon which observations or measurements are made.</p> ]]></termNote><termNote label="Definition"><![CDATA[ <p>The unit upon which observations or measurements are made.</p> ]]></termNote><termCreatedDate>Observational unit</termCreatedDate><relation><relationType>RT</relationType><termId>63</termId><termName>Sampling error</termName><termType>PT</termType></relation></term>  </Zthes>