Database and expert systems applications 31st International Conference, DEXA 2020, Bratislava, Slovakia, September 14-17, 2020 : proceedings, part II - Hartmann, Sven 1969-; Küng, Josef 1962-; Anderst-Kotsis, Gabriele 1967-; Tjoa, A Min 1952-; Khalil, Ismail 1960- (Springer, 2021)