Hani, M. K., S. Mohd Nor, S. Hussein, and N. Elfadil. “Machine Learning: The Automation of Knowledge Acquition Using Kohonen Self-Organising Map Neural Network”. Malaysian Journal of Computer Science, vol. 14, no. 1, June 2001, pp. 68-82, http://jice.um.edu.my/index.php/MJCS/article/view/5853.