Britt DM, Cohen LM, Collins FL, Cohen ML. Cigarette smoking and chewing gum: response to a laboratory-induced stressor. Health Psychol. 2001 Sep 1;20(5):361-8.
Cann CI, Fried MP, Rothman KJ. Epidemiology of squamous-cell cancer of the head and neck. Otolaryngol Clin N Am. 1985 Aug 1;18(3):367-88.