query: SELECT DISTINCT ?item ?itemLabel ?article
  	(strafter( str(?item),"y/") as ?a)
  	("P2860" as ?b)
  	("Q1203579" as ?c)
  WHERE
  { 
    BIND( '"Deutsche Musik-Zeitung"~ BLKO' as ?search)
    SERVICE wikibase:mwapi { 
        bd:serviceParam wikibase:endpoint "de.wikisource.org" ;  wikibase:api "Generator" ;
                        mwapi:generator "search" ;              mwapi:gsrsearch ?search ;
                        mwapi:gsrlimit "max" ;                  mwapi:gsrnamespace "0" .    
        ?title wikibase:apiOutput mwapi:title .
        ?item wikibase:apiOutputItem mwapi:item . 
    }
    hint:Prior hint:runFirst true.
    BIND(URI(CONCAT("https://de.wikisource.org/wiki/",?title) )  as ?article)   
    ?item wdt:P1433 wd:Q665807 .
    FILTER NOT EXISTS { ?item wdt:P2860 wd:Q1203579 }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "en,de" . }
  }