Chandra Chekuri and Sanjeev Khanna (2005). “A PTAS for the multiple knapsack problem”. SIAM Journal on Computing35 (3): 713–728. doi:10.1137/s0097539700382820.
Wu, Z. Y.; Yang, Y. J.; Bai, F. S.; Mammadov, M. (2011). “Global Optimality Conditions and Optimization Methods for Quadratic Knapsack Problems”. J Optim Theory Appl151 (2): 241–259. doi:10.1007/s10957-011-9885-4.
Gallo, G.; Hammer, P. L.; Simeone, B. (1980). “Quadratic knapsack problems”. Combinatorial Optimization. Mathematical Programming Studies. 12. pp. 132–149. doi:10.1007/BFb0120892. ISBN978-3-642-00801-6
Han, Xin; Kawase, Yasushi; Makino, Kazuhisa; Guo, He (2014-06-26). “Online removable knapsack problem under convex function”. Theoretical Computer Science. Combinatorial Optimization: Theory of algorithms and Complexity 540-541: 62–69. doi:10.1016/j.tcs.2013.09.013. ISSN0304-3975.
harvard.edu
ui.adsabs.harvard.edu
Witzgall, C. (1975). “Mathematical methods of site selection for Electronic Message Systems (EMS)”. NASA Sti/Recon Technical Report N (NBS Internal report) 76: 18321. Bibcode: 1975STIN...7618321W.
Han, Xin; Kawase, Yasushi; Makino, Kazuhisa; Guo, He (2014-06-26). “Online removable knapsack problem under convex function”. Theoretical Computer Science. Combinatorial Optimization: Theory of algorithms and Complexity 540-541: 62–69. doi:10.1016/j.tcs.2013.09.013. ISSN0304-3975.