@article{Wagner2007,
author = {Wagner, G.G. and Frick, J.R. and Schupp, J. },
title= {The German Socio-Economic Panel Study (SOEP): Scope, evolution and enhancements},
year = {2007},
doi = {10.2139/ssrn.1028709},
journal = {Schmollers Jahrbuch },
volume = {127},
pages = {139--169},
}