You are looking at the HTML representation of the XML format.
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.
See the complete documentation, or API help for more information.
<?xml version="1.0"?>
<api query-continue="0">
  <query>
    <results>
      <Abelian_group fulltext="Abelian group" fullurl="https://subwiki.org/wiki/Abelian_group">
        <printouts>
          <Modification_date>
            <value>1250024281</value>
          </Modification_date>
        </printouts>
      </Abelian_group>
      <Ampheck fulltext="Ampheck" fullurl="https://subwiki.org/wiki/Ampheck">
        <printouts>
          <Modification_date>
            <value>1446735935</value>
          </Modification_date>
        </printouts>
      </Ampheck>
      <Ref:Blog_ad fulltext="Ref:Blog ad" fullurl="https://subwiki.org/wiki/Ref:Blog_ad">
        <printouts>
          <Modification_date>
            <value>1233625259</value>
          </Modification_date>
        </printouts>
      </Ref:Blog_ad>
      <Boolean_domain fulltext="Boolean domain" fullurl="https://subwiki.org/wiki/Boolean_domain">
        <printouts>
          <Modification_date>
            <value>1446753388</value>
          </Modification_date>
        </printouts>
      </Boolean_domain>
      <Boolean_function fulltext="Boolean function" fullurl="https://subwiki.org/wiki/Boolean_function">
        <printouts>
          <Modification_date>
            <value>1446755145</value>
          </Modification_date>
        </printouts>
      </Boolean_function>
      <Boolean-valued_function fulltext="Boolean-valued function" fullurl="https://subwiki.org/wiki/Boolean-valued_function">
        <printouts>
          <Modification_date>
            <value>1446758206</value>
          </Modification_date>
        </printouts>
      </Boolean-valued_function>
      <Center fulltext="Center" fullurl="https://subwiki.org/wiki/Center">
        <printouts>
          <Modification_date>
            <value>1232473609</value>
          </Modification_date>
        </printouts>
      </Center>
      <Center_(mathematics) fulltext="Center (mathematics)" fullurl="https://subwiki.org/wiki/Center_(mathematics)">
        <printouts>
          <Modification_date>
            <value>1232473696</value>
          </Modification_date>
        </printouts>
      </Center_(mathematics)>
      <Center_of_a_group fulltext="Center of a group" fullurl="https://subwiki.org/wiki/Center_of_a_group">
        <printouts>
          <Modification_date>
            <value>1232473814</value>
          </Modification_date>
        </printouts>
      </Center_of_a_group>
      <Center_of_a_ring fulltext="Center of a ring" fullurl="https://subwiki.org/wiki/Center_of_a_ring">
        <printouts>
          <Modification_date>
            <value>1232474011</value>
          </Modification_date>
        </printouts>
      </Center_of_a_ring>
      <Characteristic_(mathematics) fulltext="Characteristic (mathematics)" fullurl="https://subwiki.org/wiki/Characteristic_(mathematics)">
        <printouts>
          <Modification_date>
            <value>1210644125</value>
          </Modification_date>
        </printouts>
      </Characteristic_(mathematics)>
      <Characteristic_subgroup fulltext="Characteristic subgroup" fullurl="https://subwiki.org/wiki/Characteristic_subgroup">
        <printouts>
          <Modification_date>
            <value>1210945037</value>
          </Modification_date>
        </printouts>
      </Characteristic_subgroup>
      <Charles_Sanders_Peirce fulltext="Charles Sanders Peirce" fullurl="https://subwiki.org/wiki/Charles_Sanders_Peirce">
        <printouts>
          <Modification_date>
            <value>1285864327</value>
          </Modification_date>
        </printouts>
      </Charles_Sanders_Peirce>
      <Choice fulltext="Choice" fullurl="https://subwiki.org/wiki/Choice">
        <printouts>
          <Modification_date>
            <value>1217867948</value>
          </Modification_date>
        </printouts>
      </Choice>
      <Circle fulltext="Circle" fullurl="https://subwiki.org/wiki/Circle">
        <printouts>
          <Modification_date>
            <value>1217975274</value>
          </Modification_date>
        </printouts>
      </Circle>
      <Complete_(mathematics) fulltext="Complete (mathematics)" fullurl="https://subwiki.org/wiki/Complete_(mathematics)">
        <printouts>
          <Modification_date>
            <value>1228872541</value>
          </Modification_date>
        </printouts>
      </Complete_(mathematics)>
      <Complete_category fulltext="Complete category" fullurl="https://subwiki.org/wiki/Complete_category">
        <printouts>
          <Modification_date>
            <value>1228872645</value>
          </Modification_date>
        </printouts>
      </Complete_category>
      <Complete_group fulltext="Complete group" fullurl="https://subwiki.org/wiki/Complete_group">
        <printouts>
          <Modification_date>
            <value>1228872736</value>
          </Modification_date>
        </printouts>
      </Complete_group>
      <Continuous_predicate fulltext="Continuous predicate" fullurl="https://subwiki.org/wiki/Continuous_predicate">
        <printouts>
          <Modification_date>
            <value>1447128656</value>
          </Modification_date>
        </printouts>
      </Continuous_predicate>
      <Ref:Copyrights fulltext="Ref:Copyrights" fullurl="https://subwiki.org/wiki/Ref:Copyrights">
        <printouts>
          <Modification_date>
            <value>1489817417</value>
          </Modification_date>
        </printouts>
      </Ref:Copyrights>
    </results>
    <printrequests>
      <printrequest label="" typeid="_wpg" mode="2" />
      <printrequest label="Modification date" typeid="_dat" mode="1" />
    </printrequests>
  </query>
</api>