Libecap, G. D., & Smith, J. L. (1999). The self-enforcing provisions of oil and gas unit operating agreements: Theory and evidence. National Bureau of Economic Research.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Libecap, Gary D., و James L. Smith. The Self-enforcing Provisions of Oil and Gas Unit Operating Agreements: Theory and Evidence. Cambridge: National Bureau of Economic Research, 1999.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Libecap, Gary D., و James L. Smith. The Self-enforcing Provisions of Oil and Gas Unit Operating Agreements: Theory and Evidence. National Bureau of Economic Research, 1999.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.