S. M. Aldabbagh, Marwan. “An Approach For Evaluation Of Semantic Performance Of Search Engines: Google, Yahoo, Msn And Hakia”. Journal of Education and Science (JES) 25, no. 4 (December 1, 2012): 124–130. Accessed August 6, 2025. https://ojs.uomosul.edu.iq/index.php/edusj/article/view/23068.