Abugassa, I. O. (1999). A study of instrumental neutron activation analysis based on ko - standardization method developed for environmental materials. Fakulti Sains Fizis dan Gunaan, Universiti Kebangsaan Malaysia.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Abugassa, Ibrahim Omar. A Study of Instrumental Neutron Activation Analysis Based on Ko - Standardization Method Developed for Environmental Materials. Bangi: Fakulti Sains Fizis dan Gunaan, Universiti Kebangsaan Malaysia, 1999.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Abugassa, Ibrahim Omar. A Study of Instrumental Neutron Activation Analysis Based on Ko - Standardization Method Developed for Environmental Materials. Fakulti Sains Fizis dan Gunaan, Universiti Kebangsaan Malaysia, 1999.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.