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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.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query>
    <pages>
      <page pageid="2083" ns="0" title="Neutral Particle PID May 2007" contentmodel="wikitext" pagelanguage="en" touched="2017-03-14T16:39:15Z" lastrevid="81425" counter="14246" length="4119" />
      <page pageid="2084" ns="0" title="Charged Particle PID May 2007" contentmodel="wikitext" pagelanguage="en" touched="2017-03-14T16:40:33Z" lastrevid="81513" counter="9623" length="3906" />
      <page pageid="2136" ns="0" title="May 29, 2007 Calorimetry" contentmodel="wikitext" pagelanguage="en" touched="2017-02-24T21:12:29Z" lastrevid="80604" counter="6842" length="4071" />
      <page pageid="2174" ns="0" title="PID Progress" contentmodel="wikitext" pagelanguage="en" touched="2017-03-14T16:40:31Z" lastrevid="81501" counter="16828" length="5786" />
      <page pageid="2267" ns="0" title="July 10, 2007 Calorimetry" contentmodel="wikitext" pagelanguage="en" touched="2017-03-14T16:38:30Z" lastrevid="81371" counter="5826" length="857" />
      <page pageid="2398" ns="0" title="October 5, 2007 Calorimetry" contentmodel="wikitext" pagelanguage="en" touched="2017-03-14T16:38:51Z" lastrevid="81397" counter="3148" length="680" />
      <page pageid="17734" ns="0" title="First measurement of near-threshold J/ψ exclusive photoproduction off the proton" contentmodel="wikitext" pagelanguage="en" touched="2019-07-17T14:45:12Z" lastrevid="93285" counter="1880" length="5812" />
      <page pageid="19766" ns="0" title="Run Wiki" contentmodel="wikitext" pagelanguage="en" touched="2021-12-16T02:21:03Z" lastrevid="109816" counter="8241" length="5425" />
    </pages>
  </query>
</api>