103 IZA Discussion Papers
IZA Discussion Paper No. 517
published in: Journal of Human Resources, 42 (2), 2007, 453-487
IZA Discussion Paper No. 219
published in: Journal of Public Economics, 2001, 82 (1), 115-146
IZA Discussion Paper No. 198
published in: European Early Childhood Education Research Journal, 2003, 11 (2), 159-175