Demetriou, Ioannis (ed.) et al., Approximation and optimization. Algorithms, complexity and applications. Based on the conference on approximation and optimization: algorithms, complexity, and applications, National and Kapodistrian University of Athens, Athens, Greece, June 29–30, 2017. Cham: Springer. Springer Optim. Appl. 145, 151-184 (2019).