TY  - RPRT
TI  - Do we need objective measures to validate self-reported smoking?
AU  - R Williams
AU  - P Gillies
PY  - 1984
DO  - 10.1016/s0033-3506(84)80006-2
UR  - https://pubmed.ncbi.nlm.nih.gov/6505137/
ID  - 6505137
ER  -