@Techreport{simperl2012asefcqpumtr, address = "Karlsruhe", author = "Elena Simperl and Barry Norton and Fabian Fl{\"o}ck and Maribel Acosta", institution = "Institute AIFB, KIT", title = "A SPARQL engine for crowdsourcing query processing using microtasks - Technical Report", year = "2012", }