J. Prakash and  K. Rajesh,  Elliptical Features Extraction Using Eigen Values of Covariance Matrices, Hough Transform and Raster Scan Algorithms.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2007, vol. 6(6). 1612 - 1617
    [viewed 08 May 2024]. Available from: https://publications.waset.org/pdf/4671.