Ali, M. A., & unknown. (1987). Investigation of nitrogen compound types in high-boiling petroleum distillates form Saudi Arabian crude oils.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Ali, Mohammed Ashraf, و unknown. Investigation of Nitrogen Compound Types in High-boiling Petroleum Distillates Form Saudi Arabian Crude Oils. 1987.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Ali, Mohammed Ashraf, و unknown. Investigation of Nitrogen Compound Types in High-boiling Petroleum Distillates Form Saudi Arabian Crude Oils. 1987.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.