Dzhaliuk , N.S. and Petrychkovych , V.M. 2021. Equivalence of matrices in the ring $M(n, R)$ and its subrings. Ukrains’kyi Matematychnyi Zhurnal. 73, 12 (Dec. 2021), 1612 - 1618. DOI:https://doi.org/10.37863/umzh.v73i12.6858.