query: select * {
    ?item1 wikibase:sitelinks 1 ;
          wdt:P1566 ?g .
    ?item2 wdt:P1566 ?g ;
           wikibase:sitelinks 0 .
    filter (?item1 != ?item2) .
    ?sitelink1 schema:about ?item1 ; schema:isPartOf <https://ceb.wikipedia.org/> ; schema:name ?pagename1 .
    filter not exists { ?sitelink2 schema:about ?item2 }
  }