Dostal, Werner; Jansen, Rolf - In: Mitteilungen aus der Arbeitsmarkt- und Berufsforschung 35 (2002) 2, pp. 232-253
"After four BIBB/IAB surveys of the labour force focusing on the gaining and use of vocational qualifications, which cover a period of about 20 years, the time has come for a provisional appraisal. The BIBB/IAB surveys are large representative surveys of 0.1% of the labour force in Germany...
