WASET
    P. Prema and  B. Ramadoss,  A Classification Scheme for Game Input and Output.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2008, vol. 18(6). 1870 - 1876
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/9892.