query: SELECT DISTINCT ?authorstring WHERE {
    ?citer wdt:P2860 ?item.
    ?item wdt:P31 wd:Q13442814 ;
          wdt:P921 ?topic;
          wdt:P2093 ?authorstring.
    MINUS { ?item wdt:P50 ?author }
    FILTER(!CONTAINS(LCASE(?authorstring), "."))
    FILTER(!regex (?authorstring, "^[A-Za-z]{1}((?= ))")).
    FILTER(!regex (?authorstring, "(?<= )[A-Za-z]{1}((?= ))")).
    
  }
  LIMIT 1000