3 IZA Discussion Papers
IZA Discussion Paper No. 990
published in: E. Berenguer (ed.), Generational Accounting in Spain, Madrid: IFS, 2005, 27-66
IZA Discussion Paper No. 667
published in: M. Herfurth, M. Kohli and K. F. Zimmermann (eds.), Arbeit in einer alternden Gesellschaft (Labor in an Aging Society), Leverkusen: Leske+Budrich, 2003, 131-177
IZA Discussion Paper No. 305
published in: Applied Economics Quarterly Supplement, 2001, 52, 127-156