@article{Llewellyn2009,
author = {David Llewellyn and Ian Lang and KM. Langa and F. Naughton and FE. Mathews},
title = {Exposure to secondhand smoke and cognitive impairment in non-smokers: national cross-sectional study with cotinine measurement. },
journal = {British Medical Journal},
year = {2009},
month = {Feb},
url = {},
}