Louis-Martin Rousseau Michel Gendreau Gilles Pesant Filippo Focacci Solving VRPTWs with Constraint Programming Based Column Generation. 199-216 2004 130 Annals OR 1-4 http://dx.doi.org/10.1023/B:ANOR.0000032576.73681.29 db/journals/anor/anor130.html#RousseauGPF04