1. H.-J. Böckenhauer, On the Inapproximability of the Metric Traveling Salesman Problem, PhD Thesis, RWTH Aachen, Germany, 2000.
2. Resource-constrained project scheduling: Notation, classification, models and methods;Brucker;European Journal of Operational Research,1999
3. Vehicle routing problem with time windows, part I: Route construction and local search algorithms;Bräysy;Transportation Science,2005
4. Vehicle routing problem with time windows, part II: Metaheuristics;Bräysy;Transportation Science,2005
5. J.-F. Cordeau, G. Desaulniers, J. Desrosiers, M.M. Solomon, F. Soumis, The VRP with time windows, SIAM Monography on Discrete Mathematics and Applications/Les Cahiers du GERAD, 2002/G-99-13, 2002/ 1999.