query: #title: Check units
  # Complex constraint from [[Property talk:P4137]]
  # Unit must to be a [[d:Q15222637|unit of speed <small>(Q15222637)</small>]]
  SELECT ?item ?unit
  WHERE {
    ?item p:P4137/psv:P4137/wikibase:quantityUnit ?unit.
    MINUS {
      ?unit wdt:P31 wd:Q15222637.
    }.
  }