Safa Khalouli Fatima Ghedjati Abdelaziz Hamzaoui Ant colony optimization for solving a bi-criteria hybrid flow shop problem. 1440-1445 2008 SMC https://doi.org/10.1109/ICSMC.2008.4811488 conf/smc/2008 db/conf/smc/smc2008.html#KhalouliGH08