SUBRAMANIAM, . B.; THOMAS, . Proof Without Words: a^2-b^2=(a+b)(a-b). Ohio Journal of School Mathematics, [S. l.], v. 99, n. 1, p. 5, 2025. Disponível em: http://voyager.janeway.systems:9999/index.php/OJSM/article/view/10523. Acesso em: 7 nov. 2026.