Primary researcher of this study is:
Friedrich, Michael, Bundesinstitut für Berufsbildung (BIBB), Bonn
Dataset: 1.0.0 (10.01.2014) doi:10.4232/1.11819
Access class: C - Data and documents are only released for academic research and teaching after the data depositor's written authorization. For this purpose the Data Archive obtains a written permission with specification of the user and the analysis intention.
More information is available at the data catalogue: study description.