Gryshchuk , S. V. 2022. “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 (1), 14 - 23. https://doi.org/10.37863/umzh.v74i1.6948.