%0 Journal Article
%T Preface by the editor of the issue
%J Žurnal Sibirskogo federalʹnogo universiteta. Matematika i fizika
%D 2021
%P 677-678
%V 14
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/JSFU_2021_14_6_a0/
%G en
%F JSFU_2021_14_6_a0