Smith VK, Evans MF, Banzhaf HS, Poulos C. Can weak substitution be rehabilitated? Environ Resour Econ (Dordr). 2010 Feb 1;45(2):203-21.
Feltner D, Hill C, Lenderking W, Williams VS, Morlock R. Development of a patient-reported assessment to identify placebo responders in a generalized anxiety disorder trial. J Psychiatr Res. 2009 Oct;43(15):1224-30.
Morlock RJ, Williams VS, Cappelleri JC, Harness J, Fehnel SE, Endicott J, Feltner D. Development and evaluation of the Daily Assessment of Symptoms – Anxiety (DAS-A) Scale to evaluate onset of symptom relief in patients with generalized anxiety disorder. J Psychiatr Res. 2008 Oct;42(12):1024-36.
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.