1.004 IZA Discussion Papers
IZA Discussion Paper No. 19
published in: Journal of Population Economics 2000, 13 (1), 57-79
IZA Discussion Paper No. 13
IZA Discussion Paper No. 12
IZA Discussion Paper No. 7
published in: Boesler, Klaus-Achim/ Heinritz, Günter/ Wiessner, Reinhard (Hrsg.), Europa zwischen Integration und Regionalismus, Franz Steiner Verlag, Stuttgart, 1998, 56-66