6 IZA Discussion Papers
IZA Discussion Paper No. 16673
IZA Discussion Paper No. 13811
IZA Discussion Paper No. 4579
published in: Papers in Regional Science, 2010, 89 (2), 435-447
IZA Discussion Paper No. 4177
published in: Empirical Economics, 2009, 37 (3), 627 - 652
IZA Discussion Paper No. 3226