Numerical Geometry, Grid Generation and Scientific Computing Proceedings of the 9th International Conference, NUMGRID 2018 / Voronoi 150, Celebrating the 150th Anniversary of G.F. Voronoi, Moscow, Russia, December 2018 - Garanzha, Vladimir A.; Garanzha, Vladimir A.; Kamenski, Lennard; Kamenski, Lennard; Si, Hang; Si, Hang (Springer International Publishing : Imprint: Springer, 2019)