DerechV. D. “Stable Quasiorderings on Some Permutable Inverse Monoids”. Ukrains’kyi Matematychnyi Zhurnal 66, no. 4 (April 25, 2014): 445–457. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2147.