European Journal of Operational Research
European Journal of Operational Research > 2001 > 133 > 1 > 62-68
European Journal of Operational Research > 2001 > 133 > 2 > 394-408
European Journal of Operational Research > 2001 > 133 > 1 > 62-68
European Journal of Operational Research > 2001 > 133 > 2 > 394-408