Al Thawab، A. A. A. A. S.، و Jones، M. (2009). Modality in English and Arabic: The Structure and Meaning of English Modal Verbs and their Equivalents in Arabic (رسالة ماجستير غير منشورة). University of Essex، إسيكس. مسترجع من http://search.mandumah.com/Record/607967
Al Thawab، Abd Alrahman Abd Allah S.، و Mike Jones. "Modality in English and Arabic: The Structure and Meaning of English Modal Verbs and Their Equivalents in Arabic" رسالة ماجستير. University of Essex، إسيكس، 2009. مسترجع من http://search.mandumah.com/Record/607967