Nhon Do and  Tam Pham,  Problem Solving Techniques with Extensive Computational Network and Applying in an Educational Software.   journal   = {International Journal of Computer and Systems Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2010, vol. 42(6). 1097 - 1103
    [viewed 26 January 2022]. Available from: https://publications.waset.org/pdf/10126.