V.Ganesh3, V.S. Sanjana Devi4, S.Sam Jai Kumar1, T.Joby Titus2,. 2016. “Automotive Crack Detection for Railway Track Using Ultrasonic Sensorz”. International Journal of Engineering Technology and Computer Research 4 (6). https://ijetcr.org/index.php/ijetcr/article/view/339.