WASET
    Shashank N. Mathur and  Anil K. Ahlawat and  Virendra P. Vishwakarma,  Illumination Invariant Face Recognition using Supervised and Unsupervised Learning Algorithms.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    July 2008, vol. 19(7). 2377 - 2382
    [viewed 27 April 2024]. Available from: https://publications.waset.org/pdf/11830.