Candrilli SD, Davis KL, Iyer S. Impact of constipation on opioid use patterns, health care resource utilization, and costs in cancer patients on opioid therapy. J Pain Palliat Care Pharmacother. 2009 Sep 1;23(3):231-41.
Chen XH, Rodríguez S, Hawe E, Talmud PJ, Miller GJ, Underhill P, Humphries SE, Day IN. Evidence of admixture from haplotyping in an epidemiological study of UK Caucasian males: implications for association analyses. Hum Hered. 2004;57(3):142-55.
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.