Kozhagulov, Y., M. Ibraimov, D. Zhexebay, and S. Sarmanbetov. “Face Detection of Integral Image by Viola-Jones Method”. Recent Contributions to Physics, vol. 2018, no. 3, Sept. 2018, pp. 76-82, https://bph.kaznu.kz/index.php/zhuzhu/article/view/638.