Astrophysics and Space Science. An International Journal of Astronomy, Astrophysics and Space Science (Astrophys. Space Sci.) (20180101), 363, no.~9, Paper No 180, 8~pp. ISSN: 0004-640X (print).eISSN: 1572-946X.
Set-Valued and Variational Analysis. Theory and Applications (Set-Valued Var. Anal.) (20190101), 27, no.~4, 1025-1027. ISSN: 1877-0533 (print).eISSN: 1877-0541.