Tadahiko Murata Akinori Taki Many-Objective Optimization for Knapsack Problems Using Correlation-Based Weighted Sum Approach. 468-480 2009 EMO http://dx.doi.org/10.1007/978-3-642-01020-0_37 conf/emo/2009 db/conf/emo/emo2009.html#MurataT09