query: PREFIX wdno: <http://www.wikidata.org/prop/novalue/>
  PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
  
  SELECT ?item ?itemLabel ?inchi ?pubid WHERE {
    #?item p:P662/a wdno:P662;  #has pubid
          ?item wdt:P235 ?inchi.
          OPTIONAL{?item wdt:P662 ?pubid}
  
  
        FILTER(!BOUND(?pubid))
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }
  
  