query: SELECT ?item ?itemLabel (COUNT(?source) AS ?count)
  WHERE {
    ?item p:P19 ?awardStat . # … with an awarded(P166) statement
    ?awardStat ps:P19 wd:Q649 . # … that has the value Nobel Prize in Chemistry (Q35637)
    ?awardStat pq:P17 ?when . # when did he receive the Nobel prize
      ?awardStat (prov:wasDerivedFrom) ?source.
  { ?when wdt:P17 wd:Q159 } UNION
    { ?when wdt:P17 wd:Q15180 } UNION
    { ?when wdt:P17 wd:Q2305208 } UNION
    { ?when wdt:P17 wd:Q34266 } UNION
    { ?when wdt:P17 wd:Q2184 }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "ru,en,cs" }
  }
  GROUP BY ?item ?itemLabel
  ORDER BY DESC (?count)