Washington, DC : The World Bank, Development Research Group, Trade and Integration Team, 2011 ; Halle (Saale) : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2011
Washington, DC : World Bank, Development Research Group, Trade and Integration Team, 2010 ; Halle (Saale) : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2010