6 IZA Discussion Papers
IZA Discussion Paper No. 17106
IZA Discussion Paper No. 13719
IZA Discussion Paper No. 12288
IZA Discussion Paper No. 11717
IZA Discussion Paper No. 8493
published in: Journal of Econometrics, 2017, 200, (2), 363-377.
IZA Discussion Paper No. 2163
published in: Journal of Econometrics, 2008, 143 (2), 274-290