R. Padilla and  C. F. F. Costa Filho and  M. G. F. Costa,  Evaluation of Haar Cascade Classifiers Designed for Face Detection.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2012, vol. 64(4). 466 - 469
    [viewed 19 November 2019]. Available from: https://publications.waset.org/pdf/2910.