query: #title: Items with P1889 and the same GeoNames ID as another item
  # Complex constraint from [[Property talk:P1566]]
  # Items explicitly marked as being different from each other are not expected to have the same GeoNames ID.
  select distinct ?item { ?item wdt:P1889 ?item2 ; wdt:P1566 ?geonames . ?item2 wdt:P1566 ?geonames . } order by ?item limit 1000