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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>
    <allredirects garcontinue="København,_Det_kongelige_Bibliotek_Slotsholmen,_Gl._Kgl._S._3449,_8o_III|1485" />
  </query-continue>
  <query>
    <pages>
      <page pageid="22" ns="0" title="Köln, Dom- und Diözesanbibliothek, Codex 1519" />
      <page pageid="101" ns="0" title="Köln, Dom- und Diözesanbibliothek, Codex 229" />
      <page pageid="102" ns="0" title="Köln, Dom- und Diözesanbibliothek, Codex 156" />
      <page pageid="127" ns="0" title="Düsseldorf, Universitätsbibliothek, D 6" />
      <page pageid="221" ns="0" title="CEEC" />
      <page pageid="222" ns="0" title="Codices Electronici Ecclesiae Coloniensis" />
      <page pageid="1375" ns="0" title="A-Gu 29" />
      <page pageid="1433" ns="0" title="Karlsruhe, Badische Landesbibliothek, Perg. Aug. 60" />
      <page pageid="1483" ns="0" title="Kopenhagen, Königliche Bibliothek, 3449, 80 I" />
      <page pageid="1484" ns="0" title="Kopenhagen, Königliche Bibliothek, 3449, 80 II" />
    </pages>
  </query>
</api>