[ 24 ] Vgl . : G. Schwerdt , J. Turunen , Growth in euro area labour quality , ECB Working Paper Series , Nr . 575 , Januar 2006 ###>[ 24 ] See G. Schwerdt and J. Turunen ( 2005 ) : « Growth in euro area labour quality » , ECB Working Paper Series , No 575 , January 2006 .