@article{Piontek2012,
author = {Piontek, D. and Kraus, L. and Pabst, A. and Legleye, S.},
title= {An age-period-cohort analysis of cannabis use prevalence and frequency in Germany, 1990-2009},
year = {2012},
doi = {10.1136/jech-2011-200180},
journal = {Journal of Epidemiology and Community Health},
volume = {66},
number = {10},
pages = {908--913},
}