1.123 IZA Discussion Papers
IZA Discussion Paper No. 207
published in: Vierteljahrshefte zur Wirtschaftsforschung / Quarterly Journal of Economic Research, 2000, 69 (3), 425-437
IZA Discussion Paper No. 128
published in: Journal of Econometrics, 2005, 125 (1-2), 53-75
IZA Discussion Paper No. 77