Majumdar, Subrata, Mohd Altab Hossain, and Kalyan Kumar Dey. “The Endomorphism Semigroup of an Endomapping of a Finite Set”. GANIT: Journal of Bangladesh Mathematical Society 31 (April 9, 2012): 71–77. Accessed January 8, 2025. https://banglajol.info/index.php/GANIT/article/view/10310.