Kozachenko, M.Y. (1988) “Necessary and sufficient condition of isomorphism for multiplicative and additive systems without continuity condition with the accuracy up to grinding divisions ”, Ukrains’kyi Matematychnyi Zhurnal, 40(5), pp. 576–583. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/8805 (Accessed: 7 April 2025).