A simple proof that the square-free numbers have density 6/(pi^2). Gulf Journal of Mathematics, [S. l.], v. 1, n. 2, 2013. DOI: 10.56947/gjom.v1i2.222. Disponível em: https://www.gjom.org/index.php/gjom/article/view/222. Acesso em: 22 aug. 2026.