M.A. Lazim and  M.T.Abu Osman,  Measuring Teachers- Beliefs about Mathematics: A Fuzzy Set Approach.   journal   = {International Journal of Educational and Pedagogical Sciences}, [online]. World Academy of Science, Engineering and Technology.
    September 2009, vol. 33(9). 1816 - 1820
    [viewed 19 April 2021]. Available from: https://publications.waset.org/pdf/13235.