Ulph, A. (2001). Environmental policy, international agreements and international trade. Oxford University Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रUlph, Alistair. Environmental Policy, International Agreements and International Trade. Oxford University Press, 2001.
एमएलए (9वां संस्करण) प्रशस्ति पत्रUlph, Alistair. Environmental Policy, International Agreements and International Trade. Oxford University Press, 2001.
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