Melih Turgut and  Süha Yılmaz,  Contributions to Differential Geometry of Pseudo Null Curves in Semi-Euclidean Space.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    July 2008, vol. 19(7). 486 - 488
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/696.