2 × 9 = 81 conversely and 9 × 9 = 18 conversely” Mathematic play of 9- year-old, the copyright and the civil law. Discourse of Law and Administration, [S. l.], n. 1, 2024. DOI: 10.61823/dpia.2024.1.414. Disponível em: https://www.dyskurs.inp.uz.zgora.pl/index.php/DPiA/article/view/414. Acesso em: 12 feb. 2026.