Ying Huang and  Zhiliang Wang and  An Ping,  Non-contact Gaze Tracking with Head Movement Adaptation based on Single Camera.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2009, vol. 35(11). 2568 - 2571
    [viewed 18 January 2020]. Available from: https://publications.waset.org/pdf/10887.