Mangel AW, Fehnel SE. End points in irritable bowel syndrome. Expert Rev Gastroenterol Hepatol. 2011 Jun 1;5(3):293-5.
Akashi-Ronquest N. The impact of biological preferences on parental investments in children and step-children. Rev Econ Househ. 2009 Mar 1;7(1):59-81.
Van Houtven CH, Wilson MR, Clipp EC. Informal care intensity and caregiver drug utilization. Rev Econ Househ. 2005;3(4):415-33.