Yong Chen 0002 Guohui Lin Tian Liu 0001 Taibo Luo Bing Su 0002 Yao Xu Peng Zhang 0008 A (1.4 + ε )-approximation algorithm for the 2-Max-Duo problem. 806-824 2020 40 J. Comb. Optim. 3 https://doi.org/10.1007/s10878-020-00621-0 db/journals/jco/jco40.html#ChenLLLSXZ20