4 IZA Discussion Papers
IZA Discussion Paper No. 8526
published in: International Encyclopedia of the Social & Behavioral Sciences, 2nd ed., 2015, Vol. 6
IZA Discussion Paper No. 160
published in: Research in Labor Economics, 2001, 20, 191-215
IZA Discussion Paper No. 137
published in: Journal of Population Economics, 2001, 14 (3), 523-548
IZA Discussion Paper No. 87
published in: Economics of Education Review, 2002, 21 (2), 221-229