Putra, T. D., and R. Purnomo. “Research on Sobel Edge Detection Algorithm of Grayscale Images to Analyse Car Number Plate”. Sinkron : Jurnal Dan Penelitian Teknik Informatika, vol. 9, no. 2, Apr. 2025, pp. 598-04, doi:10.33395/sinkron.v9i2.14538.