WASET
    N.Subramanian and  U.K.Misra,  A New Class χ2 (M, A,) of the Double Difference Sequences of Fuzzy Numbers.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    November 2009, vol. 35(11). 954 - 958
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/8161.