Volume 231, Issue 3

This issue is a translation of Problemy Matematicheskogo Analiza (Problems in Mathematical Analysis), No. 91, February 2018. Editorial Board of PMA: N. Uraltseva (Main Editor), N. Ivochkina, A. Laptev, B. Makarov, V. Maz’ya, V. Osmolovskii, B. Plamenevskii, G. Rozenblyum, D. Yafaev. Translated into English and edited by Tamara Rozhkovskaya (rozhk@math.nsc.ru)