query: SELECT ?item ?st ?sl (GROUP_CONCAT( DISTINCT (CONCAT("[[:",?l,":",?title,"|",?l,"]]"))) as ?wps)
  {
  	?item wdt:P31 wd:Q29791211 . 
      OPTIONAL { ?article schema:about ?item ; schema:inLanguage ?l ; schema:name ?title ; schema:isPartOf [ wikibase:wikiGroup 'wikipedia' ]  }
      ?item wikibase:statements ?st ; wikibase:sitelinks ?sl 
  }
  GROUP BY ?item ?st ?sl