University of Iowa, Iowa City, IA, USA published a paper on Generation system in what year?
When was the paper on Generation system by University of Iowa, Iowa City, IA, USA published?
SELECT DISTINCT ?answer WHERE { <https://dblp.org/rec/conf/iccd/PatilR89> <https://dblp.org/rdf/schema#authoredBy> ?x . ?x <https://dblp.org/rdf/schema#primaryAffiliation> 'University of Iowa, Iowa City, IA, USA' . <https://dblp.org/rec/conf/iccd/PatilR89> <https://dblp.org/rdf/schema#yearOfPublication> ?answer }
<https://dblp.org/rec/conf/iccd/PatilR89>