3 IZA Discussion Papers
IZA Discussion Paper No. 2384
published in: D. Lee (ed.), Advances in Airline Economics, Vol. 2: The Economics of Airline Institutions, Operations and Marketing, Elsevier 2007
IZA Discussion Paper No. 2364
IZA Discussion Paper No. 325
published as 'Real earnings and business cycles: new evidence' in: Empirical Economics, 2009, 37 (1), 51-71