APA (7 वां संस्करण) प्रशस्ति पत्र
Barrett, S. (2007). Why cooperate?: The incentive to supply global public goods. Oxford University Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र
Barrett, Scott. Why Cooperate?: The Incentive to Supply Global Public Goods. Oxford ; New York: Oxford University Press, 2007.
एमएलए (9वां संस्करण) प्रशस्ति पत्र
Barrett, Scott. Why Cooperate?: The Incentive to Supply Global Public Goods. Oxford University Press, 2007.
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