Dr. A.R. Madhusudana Reddy. “The Study of Mathematical Objects and Structures That Are Countable or Discrete”. African Diaspora Journal of Mathematics ISSN: 1539-854X, Multidisciplinary UGC CARE GROUP I, vol. 22, no. 2, Oct. 2023, pp. 13-22, https://newjournalzone.in/index.php/ijmfsmr/article/view/46.