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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="Deltasigma-simulation.png|1794" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1311" ns="0" title="Preface" />
      <page pageid="1332" ns="0" title="Cruise control" />
      <page pageid="1337" ns="0" title="Ball and beam system" />
      <page pageid="1719" ns="0" title="Bicycle dynamics" />
      <page pageid="1794" ns="0" title="Delta-sigma converter" />
      <page pageid="2236" ns="0" title="Congestion control" />
      <page pageid="2259" ns="0" title="Compartment model" />
      <page pageid="2297" ns="0" title="Errata: In Example 8.8, explanation of effects of poles and zeros is incorrect and confusing" />
    </pages>
  </query>
</api>