Sen, B K, Wye Keen Khong, Soo Hoon Lee, Bee Ling Lim, Mohd Rafae Abdullah, Chang Nguan Ting, and Siu Hiang Wee. 1998. “ZIPF’S LAW AND WRITINGS ON LIS”. Malaysian Journal of Library and Information Science 3 (1):93-98. https://adum.um.edu.my/index.php/MJLIS/article/view/6652.