SALOMAA, A. On basic groups for the set of functions over a finite domain. Annales Fennici Mathematici, [S. l.], n. 338, 1964. DOI: 10.5186/aasfm.1964.338. Disponível em: https://afm.journal.fi/article/view/134040. Acesso em: 26 nov. 2024.