A Tile with Nested Chain Abacus. Baghdad Science Journal, Iraq, Baghdad, v. 19, n. 3, p. 0569, 2022. DOI: 10.21123/bsj.2022.19.3.0569. Disponível em: https://bsj-ojs.uobaghdad.edu.iq/index.php/BSJ/article/view/5233.. Acesso em: 23 jun. 2025.