Varathan, K. D., T. M. Tengku Sembok, R. Abdul Kadir, and N. Omar. “Semantic Indexing For Question Answering System”. Malaysian Journal of Computer Science, vol. 27, no. 4, Dec. 2014, pp. 261-74, https://adum.um.edu.my/index.php/MJCS/article/view/6828.