Thankappan, KRMini, GK2015-07-292015-07-292008N Engl J Med. 358;26;2842-3. doi: 10.1056/NEJMc080813http://www.ncbi.nlm.nih.gov/pubmed/18579823https://dspace.sctimst.ac.in/handle/123456789/2574Public HealthCase-Control Study of Smoking and Death in India