Raghunathan K, Layton JB, Ohnuma T, Shaw AD. Observational research using propensity scores. Adv Chronic Kidney Dis. 2016 Nov;23(6):367-72. doi: 10.1053/j.ackd.2016.11.010
Mauskopf JA, Candrilli SD, Chevrou-Severac H, Ochoa JB. Immunonutrition for patients undergoing elective surgery for gastrointestinal cancer: impact on hospital costs. World J Surg Oncol. 2012 Jul 1;10:136.
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.