Kuz, A. M., and B. I. Ptashnik. 2015. “A Problem With Condition Containing an Integral Term for a Parabolic-Hyperbolic Equation”. Ukrains’kyi Matematychnyi Zhurnal 67 (5), 635-44. https://umj.imath.kiev.ua/index.php/umj/article/view/2011.