@article{Helakorpi2008,
author = {Helakorpi, S. and Martelin, T. and Torppa, J. and Vartiainen, E. and Uutela, A. and Patja, K.},
title= {Impact of the 1976 Tobacco Control Act in Finland on the proportion of ever daily smokers by socioeconomic status},
year = {2008},
doi = {10.1016/j.ypmed.2007.11.001},
journal = {Preventive Medicine},
volume = {46},
number = {4},
pages = {340--345},
}