query: SELECT ?item ?itemLabel (COUNT(?article) AS ?count) WHERE {
    ?site schema:about ?article;
          schema:isPartOf <https://zh.wikisource.org/>.
    ?article wdt:P50 ?item.
    SERVICE wikibase:label {bd:serviceParam wikibase:language "zh,zh-hant,zh-hans,[AUTO_LANGUAGE]"}
  } GROUP BY ?item ?itemLabel ORDER BY DESC(?count) ASC(?item) LIMIT 200