Chuchman, I.Ya., and O.V. Gutik. “Topological Monoids of Almost Monotone Injective Co-Finite Partial Selfmaps of the Set of Positive Integers”. Carpathian Mathematical Publications 2, no. 1 (June 30, 2010): 119–132. Accessed May 3, 2024. https://journals.pnu.edu.ua/index.php/cmp/article/view/3998.