PÉREZ-GONZÁLEZ, Juan Carlos; TRUJILLO-VÁZQUEZ, José Mario. The importance of certification. CienciaUAT, [S. l.], v. 3, n. 1, p. 26–27, 2008. Disponível em: https://revistaciencia.uat.edu.mx/index.php/CienciaUAT/article/view/417. Acesso em: 9 nov. 2026.