query: SELECT ?organization ?organizationLabel ?Twitter_username WHERE {
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
    ?organization wdt:P31 wd:Q43229;
      wdt:P17 wd:Q96.
    OPTIONAL { ?organization wdt:P2002 ?Twitter_username. }
  }
  LIMIT 1000