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| 2 | ITC-International Trade Center (2003). A Gravity Model for The Calculation of Trade Potentials for Developing Countries and Economies in Transition. TradeSim (second version), Explanatory Notes. |
| 3 | WTO and UNCTAD (2012). A Practical Guide to Trade Policy Analysis. www.wto.org/english/res_e/publications_e/wto_unctad12_e.pdf |
| 4 | Deardorff, Alan V. (1998). Determinants of Bilateral Trade: Does Gravity Work in a Neoclassical World?" In J.A. Frankel, ed., The Regionalization of the World Economy,University of Chicago Press, 7-32. |