JHA , A. C. Positional Number System. NUTA Journal, [S. l.], v. 7, n. 1-2, p. 1–9, 2020. DOI: 10.3126/nutaj.v7i1-2.39924. Disponível em: https://www.nepjol.info/index.php/nutaj/article/view/39924. Acesso em: 6 jul. 2022.