Iskenderov, B. A., and É. S. Guseinova. 2009. “Mixed Problem for the Petrovskii Well-Posed Equation in a Cylindrical Domain”. Ukrains’kyi Matematychnyi Zhurnal 61 (2): 214-30. https://umj.imath.kiev.ua/index.php/umj/article/view/3014.