5ADB working paper Increasing Gains from Trade Through Regional Cooperation in Trade Policy, Transport and Customs Transit 2006.
6Richard Pomfret, Trade Policies in Central Asia after EU Enlargement and before Russian WTO accession. Regionalism and Integration into the World Economy, School of Economics University of Adelaide University, Australia Working Paper 2004 - 13.
7James E. Anderson, A Theoretical Foundation for the Gravity Equation, The American Economic Review, Vol. 69, No. 1 (Mar. , 1979), pp. 106 -116.
8Oxana Babetskaia - Kukharchuk, Ian Babetskii and Martin Raiser, Gravity and integration . determinants of international trade in South -Eastern Europe and the former Soviet Union.
9Richard G. Lipsey, The Theory of Customs Unions . Trade Diversion and Welfare, Economica, New Series, Vol. 24, No. 93. (Feb., 1957), pp. 40-46.
10Martin Raiser and Toshiaki Sakatsume, Beyond borders. Reconsidering regional trade in Central Asia Clemens Grafe, European Bank for Reconstruction and Development.