Matthias Köppe Jiawei Wang 0010 Dual-feasible functions for integer programming and combinatorial optimization: Algorithms, characterizations, and approximations. 84-106 2022 308 Discret. Appl. Math. https://doi.org/10.1016/j.dam.2019.11.021 https://www.wikidata.org/entity/Q114191509 db/journals/dam/dam308.html#KoppeW22