United nations industrial development organization Vienna. (1973). The petrochemical industry. New York: United Nation.
استشهاد بنمط شيكاغوUnited nations industrial development organization Vienna. The Petrochemical Industry. New York: United Nation, 1973.
MLA استشهادUnited nations industrial development organization Vienna. The Petrochemical Industry. New York: United Nation, 1973.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.