MD. NASIMUZZAMAN CHOWDHURY; MD. KHALED HOSSAIN. M2M: GSM Network for Robots using DTMF. Global Journals of Research in Engineering, [S. l.], v. 13, n. F10, p. 23–29, 2013. Disponível em: https://engineeringresearch.org/index.php/GJRE/article/view/863. Acesso em: 5 may. 2024.