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.
Mansfield CA. A consistent method for calibrating contingent value survey data. South Econ J. 1998;64(3):665-81.