Chhaya Gangwal and  R. N. Bhaumik and  Shishir Kumar,  Some Properties of IF Rough Relational Algebraic Operators in Medical Databases.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    May 2014, vol. 86(2). 378 - 382
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/9998470.