S. B. Liu and  K. M. Ng and  H. L. Ong,   A New Heuristic Algorithm for the Classical Symmetric Traveling Salesman Problem .   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2007, vol. 1(1). 34 - 38
    [viewed 11 May 2024]. Available from: https://publications.waset.org/pdf/13266.