Moghaddam, A. I., and V. Ranjbar. “DIFFERENCE AMONG RANKING ALGORITHMS OF DIFFERENT WEB SEARCH TOOLS: A STATISTICAL APPROACH”. Malaysian Journal of Library and Information Science, vol. 13, no. 2, Sept. 2017, pp. 15-28, https://ajba.um.edu.my/index.php/MJLIS/article/view/6977.