query: SELECT DISTINCT ?person ?personLabel WHERE {
    ?person p:P39 ?statement .
    ?statement ps:P39 [ wdt:P279* wd:Q19953703 ] .
    FILTER NOT EXISTS { ?statement pq:P582 ?end }
    OPTIONAL { ?statement pq:P580 ?start }
    OPTIONAL {
      ?statement pq:P2937 ?term .
      FILTER NOT EXISTS { ?term wdt:P576|wdt:P582 ?term_end }
    }
    FILTER (BOUND(?start) || BOUND(?term))
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }        
  }
  