Combinatorial Optimization and Applications 13th International Conference, COCOA 2019, Xiamen, China, December 13-15, 2019, Proceedings - Li, Yingshu; Li, Yingshu; Cardei, Mihaela; Cardei, Mihaela; Huang, Yan; Huang, Yan (Springer International Publishing : Imprint: Springer, 2019)