4 IZA Discussion Papers
IZA Discussion Paper No. 10612
IZA Discussion Paper No. 10135
published in: Review of Regional Studies, 2016, 46 (3), 281-294
IZA Discussion Paper No. 3691
IZA Discussion Paper No. 3222
published in: Giornale degli Economisti ed Annali di Economia, 2007, 66 (3), 375-400