WASET
    Shin-Shin Kao and  Hsiu-Chunj Pan,  A Further Study on the 4-Ordered Property of Some Chordal Ring Networks.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    January 2015, vol. 97(1). 59 - 62
    [viewed 23 April 2024]. Available from: https://publications.waset.org/pdf/10000360.