1. INDEXES : United Nations Documentation, the Department of Public Information (DPI), Dag Hammarskjöld Library (DHL) (2007), http://www.un.org/Depts/dhl/resguide/itp.htm
2. INTERNET WORLD USERS BY LANGUAGE, Top Ten Languages Used in the Web,Internet World Stats, Usage and Population Statistics (2007)
3. T. U. o. C. UCLA, Los Angeles, “Arabic”, International Institute, Center for World Languages, Language Materials Project (2006)
4. David Graff, K.C., Kong, J., Maeda, K.: Arabic Gigaword Second Edition. Philadelphia: Linguistic Data Consortium, University of Pennsylvania (2006)
5. Schlosser, S.: ERIM Arabic Document Database, Environmental Research Institute of Michigan