by Kushnir, R. М., Makhorkin, І. М., Makhorkin, М. І.
Published in Journal of mathematical sciences (New York, N.Y.) (02.08.2022)

by Kushnir, R. М., Zhydyk, U. V., Flyachok, V. М.
Published in Journal of mathematical sciences (New York, N.Y.) (01.04.2021)

by Kushnir, R. М., Popovych, V. S., Protsyuk, B. V.
Published in Journal of mathematical sciences (New York, N.Y.) (2019)