Al Kautsar, R., 		Utaminingrum, F., & 		Budi, A.
(2021).
 Helmet Monitoring System using Hough Circle and HOG based on KNN.
<em>Lontar Komputer : Jurnal Ilmiah Teknologi Informasi, 12</em>(1), 13-23.
doi:10.24843/LKJITI.2021.v12.i01.p02