无法在DBpedia和sparql中的查询中获得结果

Question

这是我的查询，它运行正常，但没有给我任何结果。

    SELECT ?instance_of ?label_he ?label_en ?place_of_birth ?date_of_birth ?place_of_death ?date_of_death ?URL
WHERE { ?link a foaf:Person. ?link ?p ?person_full_name. 
FILTER(?p 
IN(dbo:birthName,dbp:birthName  ,dbp:fullname,dbp:name)).
  ?instance_of rdfs:label ?label_he.
  ?instance_of rdfs:label ?label_en.
  ?instance_of dbo:P19 ?place_of_birth.
  ?instance_of dbo:P569 ?date_of_birth.
  ?instance_of dbo:P20 ?place_of_death.
  ?instance_of dbo:P570 ?date_of_death.
  ?link rdfs:label ?person_name . ?person_name bif:contains "Tim_Cook" . 
  OPTIONAL { ?instance_of dbo:P31 ?record_label. }
  OPTIONAL { ?instance_of dbo:P31 ?instance_of. }
  OPTIONAL { ?instance_of dbo:P2699 ?URL. }
FILTER(langMatches(lang(?person_full_name), "en")) . } 

无法理解有什么不对 谢谢！