[1] Lindert, P.H. (1991) International Economics. 9th Edition, Homewood, Irwin.
[2] Thai Tri Do (2006) A Gravity Model of Trade between Vietnam and 23 European Countries. Department of Economics and Society, Dalarna University, Sweden.
[3] Krugman, P.R. and Maurice O. (2005) International Economics: Theory and Policy. 7th Edition, Addison-Wesley, Boston.
[4] Markusen, R.J., Melvin, R.J., Kaempfer, W. and Maskus, E.K. (1995) International Trade Theory and Evidence. McGrawHill, Boston.
[5] Dilanchiev, A. (2012) Empirical Analysis of Georgian Trade Pattern: Gravity Model. Journal of Social Sciences, 1, 75-78.
[6] Tinbergen, J. (1962) Shaping the World Economy: Suggestions for an International Economic Policy. The Twentieth Century Fund, New York.
[7] Frankel, J.A., Romer, D. and Cyrus, T. (1997) Regional Trading Blocs in the World Economic System. Institute for International Economics, Washington DC.
[8] Garman, G. and Debora, G. (1999) Economic Integration in the Americas: 1975-1992. Journal of Applied Business Research, 14, 1-12.
[9] Helpman, E.A.P.K. (1985) Market Structure and Foreign Trade: Increasing Returns, Imperfect Competition and the International Economy. MIT Press, Cambridge, MA.
[10] Bergstrand. J.H. (1989) The Generalized Gravity Equation, Monopolistic Competition, and the Factor—Proportions Theory in International Trade.
[11] Bergeijk and Brakman (2010) The Gravity Model of International Trade: Advances and Applications. Cambridge University Press, Business & Economics.
[12] Bikker, J.A. (2009) An Extended Gravity Model with Substitution Applied to International Trade. DNB Working Paper No. 215, July 2009.
[13] Elshehawy, M., Shen, H. and Ahmed, R. (2014) The Factors Affecting Egypt’s Exports: Evidence from the Gravity Model Analysis. Open Journal of Social Sciences, 2, 138-148. http://dx.doi.org/10.4236/jss.2014.211020
[14] (2009) European Union Commission Press Release Database. Brussels. http://europa.eu/rapid/press-release_IP-09-55_en.htm
[15] European Union Commission Trade. http://ec.europa.eu/trade/policy/countries-and-regions/regions/central-africa/
[16] European External Action Service. http://www.eeas.europa.eu/cameroon/index_en.htm
[17] Pougala, J.-P. (2013) Cameroon-EPA: Why Cameroon Should Not Sign the Final Ape Agreement. http://pougala.org/why-cameroon-should-not-sign-the-final-ape-agreement/
[18] Batra, A. (2006) India’s Global Trade Potential: The Gravity Model Approach. Global Economic Review, 35, 327-361. http://dx.doi.org/10.1080/12265080600888090
[19] Rahman, M.M. (2003) A Panel Data Analysis of Bangladesh’s Trade: The Gravity Model Approach. Proceedings of the 5th European Trade Study Group Conference, Madrid, 11-13 September 2003, 1-54.
[20] Sharma, S.C. and Chua, S.Y. (2000) ASEAN: Economic Integration and Intra-Regional Trade. Applied Economics Le- tters, 7, 165-169. http://dx.doi.org/10.1080/135048500351726
[21] Eurostat Comext, Directorate-General for Trade of the European Commission. http://trade.ec.europa.eu/doclib/docs/2006/september/tradoc_122457.pdf