5ALONSO, W. 1987. "Gravity Models", in J. Eatwell, M. Milgate and P. Newman (eds.),The New Palgrave: A Dictionary of Economics, Volume 2.London: Macmillan, pp.561-562
6IMF. World Economic Outlook: Trade and Finance. Washington, D. C.: IMF, 2002.
7ITC (International Trade Center). "TradeSim-The ITC Simulation Model of Bilateral Trade Potentials: Background Paper. " Document prepared by ITC market analysis section, final draft, 2000.
8Kalbasi, H. "The Gravity Model and Global Trade Flows. "2001, http://www, ecomod.net/conferences/ecomod2001/papers-web/KALBASI, pdf.
9Linnemann, H. An Econometric Study in International Trade Flows. Amsterdam: Elsevier, 1966.
10Anderson, J. "A Theoretical Foundation of the Gravity Model. " American Economic Review 69 (1), 1979.