WASET
    K. Kannan and  D. Narasimhan and  K. Chandrasekhara Rao and  R. Ravikumar,  Regular Generalized Star Star closed sets in Bitopological Spaces.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    June 2011, vol. 54(6). 816 - 818
    [viewed 27 April 2024]. Available from: https://publications.waset.org/pdf/15440.