Schmitt CL, Allen JA, Kosa KM, Curry LE. Support for a ban on tobacco powerwalls and other point-of-sale displays: findings from focus groups. Health Educ Res. 2015 Feb;30(1):98-106. doi: 10.1093/her/cyu046.
Cohen LM, Britt DM, Collins FL, Stott HD, Carter LC. Chewing gum affects smoking topography. Exp Clin Psychopharmacol. 1999 Nov 1;7(4):444-7.