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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-continue>
    <allfileusages gafcontinue="BioinformaticsCore-2011.ppt" />
  </query-continue>
  <query>
    <pages>
      <page pageid="4275" ns="6" title="File:BIST-Portada-Cursos-BioStatistics-2.jpg" />
      <page pageid="4285" ns="6" title="File:BIST Module3 practicum.zip" />
      <page pageid="4468" ns="6" title="File:BIST Module5 hands on.zip" />
      <page pageid="5018" ns="6" title="File:Bce00230.nativeT samelayerF.multi.png" />
      <page pageid="4524" ns="6" title="File:Bean-01.jpg" />
      <page pageid="3984" ns="6" title="File:BioCore Stat 2015.pptx" />
      <page pageid="3420" ns="6" title="File:BioCore advisory mtg June 22 2015.pptx" />
      <page pageid="6808" ns="6" title="File:Biocore 2018.jpg" />
      <page pageid="5189" ns="6" title="File:Biocore flyer Feb 2017.pdf" />
      <page pageid="785" ns="6" title="File:BioinformaticsCore-2011.pdf" />
    </pages>
  </query>
</api>