3 IZA Discussion Papers
IZA Discussion Paper No. 3209
published in: Bulletin of Comparative Labour Relations, 2008, 65, 235-254
IZA Discussion Paper No. 1205
published in: Applied Economics, 2007, 39 (18), 2279–2301
IZA Discussion Paper No. 529
published in: Labour Economics, 2002, 9 (5), 631-641