KOZACHENKO, M. Yu. 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, [S. l.], v. 40, n. 5, p. 576–583, 1988. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8805. Acesso em: 7 apr. 2025.