Question: Which key person of maryland jockey club is the appointer of Joseph Clay ?
SPARQL query:
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
 SELECT DISTINCT ?uri WHERE { <http://dbpedia.org/resource/Joseph_Clay_(Georgia)> onto:appointer ?uri. <http://dbpedia.org/resource/Maryland_Jockey_Club> prop:keyPeople ?uri}