query: SELECT ?item ?itemLabel ?title ?instance_of ?instance_ofLabel
  WHERE
  {
    VALUES ?search_string { "book" }
    SERVICE wikibase:mwapi { 
        bd:serviceParam wikibase:endpoint "en.wikibooks.org" ; 
                        wikibase:api "Generator" ;
                        mwapi:generator "search" ;              
                        mwapi:gsrsearch ?search_string ;
                        mwapi:gsrlimit "max" ;                  
                        mwapi:gsrnamespace "0" .    
        ?title wikibase:apiOutput mwapi:title .      
        ?item wikibase:apiOutputItem mwapi:item . 
    }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en" }
  }
  LIMIT 10