Walimbe, A., S. Rao, A. Sureban, and M. Shah. “Survey on Obstacle Detection and Its Notification through an Android App for Visually Impaired People”. Asian Journal For Convergence In Technology (AJCT) ISSN -2350-1146, Vol. 3, no. 3, Jan. 2018, http://www.asianssr.org/index.php/ajct/article/view/244.