The Guildford Documents
Tobacco industry documents "show that the industry conducted extensive research into ways to enhance and fortify the nicotine in cigarettes and tried to cope with the shrinking market for the product by using sophisticated 'lifestyle' advertisements aimed at young people. It also introduced 'light' cigarettes to try to prevent health conscious smokers from quitting."
http://www.cctc.ca/NCTHweb.nsf/35e6ce3c8d94c333852569c8006725c8/129c682000236817852569bd0048c997?OpenDocument.