Wesselink AK, Wise LA, Rothman KJ, Hahn KA, Mikkelsen EM, Mahalingaiah S, Hatch EE. Caffeine and caffeinated beverage consumption and fecundability in a preconception cohort. Reprod Toxicol. 2016 Jul;62:39-45. doi: 10.1016/j.reprotox.2016.04.022
Mangel AW, Wang J, Sherrill B, Gnanasakthy A, Ervin C, Fehnel SE. Urgency as an endpoint in irritable bowel syndrome. Gastroenterology Research. 2011 Feb 1;4(1):9-12.