Gryshchuk S. V. “Monogenic Functions With Values in Commutative Complex Algebras of the Second Rank With Unity and the Generalized Biharmonic Equation With Double Characteristics”. Ukrains’kyi Matematychnyi Zhurnal 74, no. 1 (January 24, 2022): 14 - 23. Accessed November 23, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/6948.