4 IZA Policy Papers
IZA Policy Paper No. 131
Published in Portuguese Economic Journal, 2017, Volume 16, Nº 3.
IZA Policy Paper No. 29
based on the introduction to a special issue of: Economics of Education Review, 2011, 30 (6), 1118-1122
IZA Policy Paper No. 3
also available as OECD Social, Employment and Migration Working Paper