WASET
    Jeffrey L. Duffany,  Complexity Analysis of Some Known Graph Coloring Instances.   journal   = {International Journal of Electrical and Computer Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2010, vol. 39(3). 392 - 398
    [viewed 19 September 2024]. Available from: https://publications.waset.org/pdf/10062.