DomshaO., and ZabavskiiB. V. “Block-Diagonal Reduction of Matrices over an $n$-Simple Bézout Domain $(n ≥ 3)$”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 62, no. 2, Feb. 2010, pp. 275–280, https://umj.imath.kiev.ua/index.php/umj/article/view/2864.