Qianhong Zhang and  Lihui Yang and  Daixi Liao and ,  On the Fuzzy Difference Equation xn+1 = A +.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    March 2011, vol. 51(3). 490 - 495
    [viewed 26 January 2022]. Available from: https://publications.waset.org/pdf/1158.