You should use at least 3 different sources for your essay, with a minimum of two from the list below:
1) Begg, D., Fischer, S. & Dornbusch, R. (2008) Economics, 9th edition, McGraw-Hill, ch.28
2) Griffiths, A. & Wall, S. (2012) Applied Economics, 12th edition, Longman, chapter 26
3) Sloman, J., Wride, A. & Garratt, D. (2012) Economics, 8th edition, London: Prentice Hall, chapter 25
4) E-book “The New Palgrave Dictionary of Economics Online”
5) Mankiw, N. & Taylor, M. (2011) Economics, 2nd edition, chapter 38
6) Krugman, P., Wells, R. & Graddy, K. (2008) Economics, European Edition,Worth, chp. 34.