R. K. Tuli,  Codes and Formulation of Appropriate Constraints via Entropy Measures.   journal   = {International Journal of Physical and Mathematical Sciences}, [online]. World Academy of Science, Engineering and Technology.
    March 2011, vol. 51(3). 305 - 309
    [viewed 26 January 2020]. Available from: https://publications.waset.org/pdf/927.