Price MA, Hill CD, Williams VSL, Morlock RJ, Leeuwenkamp O, Patterson TL. Measures of functional status and quality-of-life in schizophrenia. Curr Psychiatry Rev. 2008 Feb 1;4(1):28-38.
Phanikumar CV, Maitra B. Willingness-to-pay and preference heterogeneity for rural bus attributes. J Transp Eng A-Syst. 2007 Jan;133(1).