B. I. Islomov, J. A. Xolbekov, “On a nonlocal boundary-value problem for a loaded parabolic-hyperbolic equation with three lines of degeneracy”, Vestn. Samar. Gos. Tekhn. Univ., Ser. Fiz.-Mat. Nauki [J. Samara State Tech. Univ., Ser. Phys. Math. Sci.], 25:3 (2021), 407–422