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.
Smith VK, Evans MF, Banzhaf HS, Poulos C. Can weak substitution be rehabilitated? Environ Resour Econ (Dordr). 2010 Feb 1;45(2):203-21.
Mansfield CA. Despairing over disparities: an empirical analysis of the relationship between willingness-to-pay and willingness-to-accept. Environ Resour Econ (Dordr). 1999;13(2):219-34.