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>
    <alllinks galcontinue="Buyology|31" />
  </query-continue>
  <query>
    <pages>
      <page pageid="8" ns="0" title="Por qué compramos" />
      <page pageid="9" ns="0" title="Experimento eficacia advertencias cajetillas de tabaco" />
      <page pageid="11" ns="0" title="Gemma Calvert" />
      <page pageid="13" ns="0" title="Núcleo accumbens" />
      <page pageid="16" ns="0" title="Tipografía de estado estable (SST)" />
      <page pageid="17" ns="0" title="Experimento Pepsi-CocaCola" />
      <page pageid="22" ns="0" title="John Wanamaker" />
      <page pageid="26" ns="0" title="Inteligencia Intuitiva (Blink)" />
      <page pageid="28" ns="0" title="Putamen ventral" />
      <page pageid="30" ns="0" title="Corteza prefrontal interna" />
    </pages>
  </query>
</api>