Mostafa، N. S.، و Voss، B. E. (1985). COGNITIVE DEVELOPMENT,SPATIAL ABILITY, AND ACHIEVEMENT IN SCIENCE AMONG SAUDI ARABI AN STUDENTS (رسالة دكتوراه غير منشورة). University of Michigan، آنآربر. مسترجع من http://search.mandumah.com/Record/615225
Mostafa، Nidhal Shaban، و Burton E. Voss. "COGNITIVE DEVELOPMENT,SPATIAL ABILITY, AND ACHIEVEMENT IN SCIENCE AMONG SAUDI ARABI AN STUDENTS" رسالة دكتوراه. University of Michigan، آنآربر، 1985. مسترجع من http://search.mandumah.com/Record/615225