Question: Who is the producer of the song which is the previous work of He's a Liar ?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX res: <http://dbpedia.org/resource/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { <http://dbpedia.org/resource/He's_a_Liar> onto:previousWork ?x . ?x onto:producer ?uri . ?x rdf:type onto:Song}