(1971). Selected documents of the international petroleum industry. Vienna: Organization of the Petroleum Exporting Countries.
استشهاد بنمط شيكاغوSelected Documents of the International Petroleum Industry. Vienna: Organization of the Petroleum Exporting Countries, 1971.
MLA استشهادSelected Documents of the International Petroleum Industry. Vienna: Organization of the Petroleum Exporting Countries, 1971.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.