Amer, Shaymaa. “Pseudo C-M-Injective and Pseudo C-Quasi Principally Injective Systems Over Monoids”. Journal of Progressive Research in Mathematics 6, no. 3 (January 26, 2016): 778-802. Accessed April 16, 2024. http://scitecresearch.com/journals/index.php/jprm/article/view/580.