Mert Bal and  Hayri Sever and  Oya Kalıpsız,  Modeling the Symptom-Disease Relationship by Using Rough Set Theory and Formal Concept Analysis.   journal   = {International Journal of Medical and Health Sciences}, [online]. World Academy of Science, Engineering and Technology.
    November 2007, vol. 11(11). 586 - 590
    [viewed 21 September 2020]. Available from: https://publications.waset.org/pdf/8051.