Vietnam journal of mathematics : Numerical Mathematics and Control Special Issue Dedicated to Volker Mehrmann on the Occasion of his 65th Birthdey Volume 48. Number 4 / Peter Benner, Daniel Kressner, Hoang Xuan Phu,...[et al.] .- H. : Vietnam academy of science and technology & Vietnamese mathematics society , 2020 .- :; 23cm - Four issues per year - 12/2020