KhachatryanK. A., and Andriyan S. M. “On the Solvability of a Class of Discrete Matrix Equations With a Cubic Nonlinearity”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 71, no. 12, Dec. 2019, pp. 1667-83, http://umj.imath.kiev.ua/index.php/umj/article/view/186.