Mangel AW, Fehnel SE. End points in irritable bowel syndrome. Expert Rev Gastroenterol Hepatol. 2011 Jun 1;5(3):293-5.
Grzywacz JG, Quandt SA, Early J, Tapia J, Graham CN, Arcury TA. Leaving Family for Work: ambivalence and Mental Health Among Mexican Migrant Farmworker Men. J Immigr Minor Health. 2006 Jan 1;8(1):85-97.