@article{Langhammer2012,
author = {Langhammer, A. and Krokstad, S. and Romundstad, P. and Heggland, J. and Holmen, J.},
title= {The HUNT study: Participation is associated with survival and depends on socioeconomic status, diseases and symptoms},
year = {2012},
doi = {10.1186/1471-2288-12-143},
volume = {12},
number = {143},
pages = {1--14},
}