Peter Korosec Jurij Silc Klemen Oblak Franc Kosel Optimizing the Shape of an Impeller Using the Differential Ant-Stigmergy Algorithm. 520-529 2007 PPAM http://dx.doi.org/10.1007/978-3-540-68111-3_54 conf/ppam/2007 db/conf/ppam/ppam2007.html#KorosecSOK07