Utilizing an Obsolete Mobile Phone as a GSM Modem for an SMS-Based Alarm System. Asia Pacific Journal of Social Innovation, [S. l.], v. 20, n. 1, p. 185–202, 2024. Disponível em: https://journals.msuiit.edu.ph/tmf/article/view/251. Acesso em: 2 may. 2026.