Nozha Zribi Imed Kacem Abdelkader E. Kamel Pierre Borne Assignment and Scheduling in Flexible Job-Shops by Hierarchical Optimization. 652-661 2007 37 IEEE Transactions on Systems, Man, and Cybernetics, Part C 4 http://doi.ieeecomputersociety.org/10.1109/TSMCC.2007.897494 db/journals/tsmc/tsmcc37.html#ZribiKKB07