Kurinnyi, G. Ch. “Congruences and Quasiidentities on Unars”. Ukrains’kyi Matematychnyi Zhurnal 49, no. 6 (June 25, 1997): 852–856. Accessed May 20, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5072.