Kaučikas, Algirdas. “Left Permutable Multiplicative Sets and Left Strongly Prime Ideals in Rings”. Lietuvos matematikos rinkinys 48, no. proc. LMS (December 21, 2008): 23–26. Accessed November 7, 2025. https://www.zurnalai.vu.lt/LMR/article/view/18051.