Chobanov, Georgi, and Ivan Dimovski. “Extension of the Duhamel Principle for the Heat Equation With Dezin’s Initial Condition”. Ann. Sofia Univ. Fac. Math. and Inf. 93 (December 12, 2001): 73–92. Accessed April 27, 2025. https://ftl5.uni-sofia.bg./index.php/fmi/article/view/205.