Dubrovin, R. M.
Pisarev, R. V.
Article History
Received: 19 February 2020
Revised: 19 February 2020
Accepted: 6 March 2020
First Online: 6 September 2020
ADDITIONAL INFORMATION
: This article was prepared for the special issue dedicated to the centenary of A.S. Borovik-Romanov.