P.Arunthathi, R.Keerthana, R.Kiruthika, M.Vennkatesan, & Gobalakrishnan. (2017). Automatic solar powered college bell system using GSM . International Journal of Intellectual Advancements and Research in Engineering Computations, 5(2), 1238–1240. Retrieved from https://ijiarec.com/ijiarec/article/view/1673