Institution: | 1. Institute Camille Jordan UMR CNRS 5208, University of Lyon, 23 rue P. Michelon, 42023, Saint-Etienne.grigory.panasenko@univ-st-etienne.fr;3. Faculty of Mathematics and Informatics, Vilnius University, Naugarduko Str., 24, LT-03225, Vilnius, Lithuania. |