1. Alizadeh, F., Karp, R. M., Newberg, L. A. and Weisser, D. K., “Physical Mapping of Chromosomes: a Combinatorial Problem in Molecular Biology” in SODA ’93: Proc. of the 4th Annual ACM-SIAM Symposium on Discrete algorithms, isbn: 0-89871-313-7, Society for Industrial and Applied Mathematics, Philadelphia, PA, USA, pp. 371–381, 1993.
2. Allender E., Baul M., Immerman N., Schnoor H., Vollmer H.: “The Complexity of Satisfiability Problems: Refining Schaefer’s Theorem.”. J. Comput. Sys. Sci 75, 245–254 (2009)
3. Applegate, D. L., Bixby, R. E., Chvatal, V. and Cook, W. J., The Traveling Salesman Problem: A Computational Study (Princeton Series in Applied Mathematics), Princeton University Press, 2007.
4. Arkin, E. M., Chiang, Y., Mitchell, J. S. B., Skiena, S. S. and Yang, T., “On the Maximum Scatter TSP,” in SODA ’97: Proc. of the 8th Annual ACM-SIAM Symposium on Discrete algorithms, isbn: 0-89871-390-0, Society for Industrial and Applied Mathematics, Philadelphia, PA, USA, pp. 211–220, 1997.
5. Balas E.: “The Prize Collecting Traveling Salesman Problem”. Networks 19, 621–636 (1989)