(1971). Selected documents of the international petroleum industry. Vienna: Organization of the Petroleum Exporting Countries.
Trích dẫn kiểu ChicagoSelected Documents of the International Petroleum Industry. Vienna: Organization of the Petroleum Exporting Countries, 1971.
Trích dẫn MLASelected Documents of the International Petroleum Industry. Vienna: Organization of the Petroleum Exporting Countries, 1971.
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