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HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
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<?xml version="1.0"?>
<api>
  <query-continue>
    <links plcontinue="1|0|MLA_documentation_style_for_citing_sources_from_the_World_Wide_Web" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Main Page">
        <links>
          <pl ns="0" title="1914 Documents" />
          <pl ns="0" title="1915 Documents" />
          <pl ns="0" title="1916 Documents" />
          <pl ns="0" title="1917 Documents" />
          <pl ns="0" title="1918 Documents" />
          <pl ns="0" title="Books, Special Topics and Commentaries" />
          <pl ns="0" title="Conventions and Treaties" />
          <pl ns="0" title="Diaries, Memorials, Personal Reminiscences" />
          <pl ns="0" title="Disclaimer and Copyright Notice" />
          <pl ns="0" title="Links to Other WWI Sites" />
        </links>
      </page>
    </pages>
  </query>
</api>