Helal، A. A. M.، و Neal، F. W. (1981). THE PROBLEM OF EXTRACTIVE TECHNOLOGY TRANSFER FROM THE MULTINATIONAL CORPORATION TO THE HOST COUNTRIES: THE CASE OF THE RICH, UNDERDEVELOPED COUNTRIES (رسالة دكتوراه غير منشورة). Claremont Graduate University، كلاريمونت. مسترجع من http://search.mandumah.com/Record/613481
Helal، Abd Almohsin Mohammad، و Fred Warner Neal. "THE PROBLEM OF EXTRACTIVE TECHNOLOGY TRANSFER FROM THE MULTINATIONAL CORPORATION TO THE HOST COUNTRIES: THE CASE OF THE RICH, UNDERDEVELOPED COUNTRIES" رسالة دكتوراه. Claremont Graduate University، كلاريمونت، 1981. مسترجع من http://search.mandumah.com/Record/613481