Садыбеков, М. А., Г. Дилдабек, and А. А. Тенгаева. “On a New Nonlocal Boundary Value Problem for an Equation of the Mixed Parabolic-Hyperbolic Type”. Journal of Mathematics, Mechanics and Computer Science, vol. 88, no. 1, Nov. 2017, pp. 55-66, https://bm.kaznu.kz/index.php/kaznu/article/view/330.