w4.
William H. Branson (1979), Macroeconomic Theory and Policy, chapter 2; David Begg et al. (1984), Economics, chapters 19, 29; Boyle and Simms (2009), pp 37–39.
William H. Branson (1979), Macroeconomic Theory and Policy, chapter 2; David Begg et al. (1984), Economics, chapters 19, 29; Boyle and Simms (2009), pp 37–39.