3 IZA Discussion Papers
IZA Discussion Paper No. 12031
IZA Discussion Paper No. 3482
published in: Wirtschaft und Gesellschaft, 2009, 35(1), 13-43
IZA Discussion Paper No. 3198
published in: History & Mathematics: Processes and Models of Global Dynamics, Volgograd, Russia, 2010, 92 – 137