Dzhaliuk , N. S., and V. M. Petrychkovych. “Equivalence of Matrices in the Ring $M(n, R)$ and Its Subrings”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 73, no. 12, Dec. 2021, pp. 1612 -18, doi:10.37863/umzh.v73i12.6858.