1. Mishra, M. Swain and B. Dash, An Approach to Face Recognition of 2-D Images Using Eigen Faces and PCA, Signal & Image Processing : An International Journal (SIPIJ) Vol.3, No.2, 2012.
2. K. Datta, M. Datta, P. K. Banerjee, Face Detection and Recognition Theory and Practice, by Taylor & Francis Group, LLC, 2016.
3. Nabatchian, Human Face Recognition, A Dissertation Submitted to the Faculty of Graduate Studies through the Department of Electrical and Computer Engineering in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy at the University of Windsor, Windsor, Ontario, Canada ,2011.
4. O. Arandjelovic, Crowd Detection from Still Images, the British Machine Vision Association, 2008.
5. Stan Z. Li Anil K. Jain, Handbook of Face Recognition, 2nd Edition, Springer-Verlag London Limited 2011.