J. Prakash and  K. Rajesh,  Human Face Detection and Segmentation using Eigenvalues of Covariance Matrix, Hough Transform and Raster Scan Algorithms.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2008, vol. 15(3). 707 - 715
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/14841.