5 IZA Discussion Papers
IZA Discussion Paper No. 16053
IZA Discussion Paper No. 12237
published in: Applied Economics Letters, 2020, 27 (3), 194 - 198.
IZA Discussion Paper No. 5714
IZA Discussion Paper No. 4069
published in: Economics of Education Review, 2011, 30 (2), 215-227
IZA Discussion Paper No. 426
revised version published in: Labour Economics, 2007, 14(6), 926-937