query: SELECT ?author  ?authorLabel ?paper ?genderLabel ?age_num WHERE {
    ?paper wdt:P31 wd:Q13442814 .
    ?paper wdt:P577 ?date .
    ?paper wdt:P50 ?author .
    ?author wdt:P27 wd:Q408 .
    ?author wdt:P569 ?dob .
    ?author wdt:P21 ?gender .
    SERVICE wikibase:label {
      bd:serviceParam wikibase:language "en" .
     }
    bind( year(?date)-year(?dob) as ?age_num )
    FILTER(year(?date)>=1900)
    FILTER(BOUND(?age_num))
  }
  