SAMPSON, M. I.; ZSOLT, L.; ACHUOBI, J. O.; IGIRI, C.; ESSIEN, L. E. On Independence and Minimal Generating Set in Semigroups and Countable Systems of Semigroups. International Journal of Mathematical Analysis and Modelling, [S. l.], v. 6, n. 2, 2023. Disponível em: https://journal.tnsmb.org/index.php/ijmam/article/view/89. Acesso em: 12 sep. 2026.