K.Geeth Vimal Kumar, G.Shruthi, N. Uma Sundari3, G.Vivek, P.Manivara Kumar. “DIGITAL CLOCK USING AT89C5”. International Journal of Research Science and Management, vol. 3, no. 2, Feb. 2016, pp. 51-55, http://ijrsm.com/index.php/journal-ijrsm/article/view/525.