Britt (DiBenedetti) DM, Collins FL, Cohen LM. Cigarette smoking and chewing gum use among college students. J Appl Biobehav Res. 2007 Jun 4;4(2):85-90. doi: 10.1111/j.1751-9861.1999.tb00057.x
Finkelstein EA, Ruhm C, Kosa KM. Economic causes and consequences of obesity. Annu Rev Public Health. 2005;26:239-57.