Vaghela, H. R., A. A. . Amin, and P. N. . Patel. “Traffic Signal Coordination by Simple Progressive System on Selected Stretch of Ahmedabad”. International Journal of Technical Innovation in Modern Engineering & Science, vol. 4, no. 5, May 2018, pp. 488-97, https://ijtimes.com/index.php/ijtimes/article/view/1491.