103 IZA Discussion Papers
IZA Discussion Paper No. 1533
published in: Journal of Population Economics, 2006, 19 (4), 703-723
IZA Discussion Paper No. 1149
published in: Journal of Economic Behavior and Organization, 2008, 66(3-4), 529-557
IZA Discussion Paper No. 562
published in: John T. Addison and Claus Schnabel (eds.), International Handbook of Trade Unions, Cheltenham and Northampton, 2003, 415-460