Al Shenaifi، M. S.، و Stewart، B. R. (1983). CROP PRODUCTION ACTIVITIES PERFORMED BY FARMERS AND AGRICULTURAL EXTENSION WORKERS IN QASIM, SAUDI ARABIA (رسالة دكتوراه غير منشورة). University of Missouri، كولومبيا. مسترجع من http://search.mandumah.com/Record/616023
Al Shenaifi، Mohammed Saleh، و Bob R. Stewart. "CROP PRODUCTION ACTIVITIES PERFORMED BY FARMERS AND AGRICULTURAL EXTENSION WORKERS IN QASIM, SAUDI ARABIA" رسالة دكتوراه. University of Missouri، كولومبيا، 1983. مسترجع من http://search.mandumah.com/Record/616023