query: SELECT ?item ?type ?person  WHERE {  
      ?person p:P39 ?position_statement .
      ?position_statement ps:P39 wd:Q17592486 .
      ?position_statement pq:P768 ?item .
      ?item wdt:P31 ?type .
      FILTER NOT EXISTS { ?item wdt:P31 wd:Q28657263 }
    }