Christos Nomikos Aris Pagourtzis Stathis Zachos Randomized and Approximation Algorithms for Blue-Red Matching. 715-725 2007 conf/mfcs/2007 MFCS http://dx.doi.org/10.1007/978-3-540-74456-6_63 db/conf/mfcs/mfcs2007.html#NomikosPZ07