APA-viite (7. p.)
Barrett, S. (2007). Why cooperate?: The incentive to supply global public goods. Oxford University Press.
Chicago-viite (17. p.)
Barrett, Scott. Why Cooperate?: The Incentive to Supply Global Public Goods. Oxford ; New York: Oxford University Press, 2007.
MLA-viite (9. p.)
Barrett, Scott. Why Cooperate?: The Incentive to Supply Global Public Goods. Oxford University Press, 2007.
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