APA-ийн эшлэл(7 дахь хэвлэлт)

Collier, P. (2007). The bottom billion: Why the poorest countries are failing and what can be done about it. Oxford University Press.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Collier, Paul. The Bottom Billion: Why the Poorest Countries Are Failing and What Can Be Done About It. Oxford ; New York: Oxford University Press, 2007.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Collier, Paul. The Bottom Billion: Why the Poorest Countries Are Failing and What Can Be Done About It. Oxford University Press, 2007.