Abo Heimed، I.، و Shivtiel، A. (1991). Linguistic Analysis of Diglossia in Arabic and its Implications for Teaching Arabic to Non-Arabs in Riyadh ( Saudi Arabia ) (رسالة دكتوراه غير منشورة). University of Leeds، ليدز. مسترجع من http://search.mandumah.com/Record/600696
Abo Heimed، Ibrahim، و Avihai Shivtiel. "Linguistic Analysis of Diglossia in Arabic and Its Implications for Teaching Arabic to Non-Arabs in Riyadh ( Saudi Arabia )" رسالة دكتوراه. University of Leeds، ليدز، 1991. مسترجع من http://search.mandumah.com/Record/600696