Khôi, L. H. “Algorithms for Finding Closure of the Facts SCL and Removing Redundant Redundant Rules of the Rules Set in the Rule-Based System of the Expert System”. Journal of Computer Science and Cybernetics, vol. 16, no. 4, Apr. 2013, pp. 79-85, doi:10.15625/1813-9663/16/4/2926.