Ervin CM, Mangel AW. Clinical trials in irritable bowel syndrome: a review. Rev Recent Clin Trials. 2013 Mar 1;8(1):9-22.
Carrera G, Garcia-Albeniz X, Ayuso JR, Aparicio J, Castells A, Codony-Servat J, Feliu J, Fuster D, Gallego R, Pages M, Torres F, Maurel J. Design and endpoints of clinical and translational trials in advanced colorectal cancer. a proposal from GROUP Español Multidisciplinar en Cancer Digestivo (GEMCAD). Rev Recent Clin Trials. 2011 May;6(2):158-70. doi: 10.2174/157488711795177868
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.
Watson V, Ryan M. Exploring preference anomalies in double bounded contingent valuation. J Health Econ. 2007 May 1;26(3):463-82. doi: 10.1016/j.jhealeco.2006.10.009