6 IZA Discussion Papers
IZA Discussion Paper No. 15989
IZA Discussion Paper No. 12368
IZA Discussion Paper No. 11830
IZA Discussion Paper No. 11510
IZA Discussion Paper No. 6668
published in: Scottish Journal of Political Economy, 2012, 59 (5), 523 - 542
IZA Discussion Paper No. 4479