European Journal of Operational Research
European Journal of Operational Research > 2009 > 198 > 1 > 84-92
European Journal of Operational Research > 2009 > 198 > 1 > 215-222
European Journal of Operational Research > 2009 > 198 > 1 > 84-92
European Journal of Operational Research > 2009 > 198 > 1 > 215-222