Al Shehri، A. A. S. A.، و Hawkins، R. (1993). Urbanisation and linguistic variation and change: A sociolinguistic study of the impact of urbanisation on the linguistic behaviour of urbanised rural immigrants in Hijaz, Saudi Arabia (رسالة دكتوراه غير منشورة). University of Essex، إسيكس. مسترجع من http://search.mandumah.com/Record/599943
Al Shehri، Abd Allah S. A.، و Roger Hawkins. "Urbanisation and Linguistic Variation and Change: A Sociolinguistic Study of the Impact of Urbanisation On the Linguistic Behaviour of Urbanised Rural Immigrants in Hijaz, Saudi Arabia" رسالة دكتوراه. University of Essex، إسيكس، 1993. مسترجع من http://search.mandumah.com/Record/599943