Jeffrey Junfeng Pan Qiang Yang Co-Localization from Labeled and Unlabeled Data Using Graph Laplacian. 2166-2171 2007 conf/ijcai/2007 IJCAI http://dli.iiit.ac.in/ijcai/IJCAI-2007/PDF/IJCAI07-349.pdf db/conf/ijcai/ijcai2007.html#PanY07