Johnson FR, Mansfield CA. Survey-design and analytical strategies for better healthcare stated-choice studies. Patient. 2008;1(4):299-307.
McCrink L, Allen RP, Wolowacz SE, Sherrill B, Connolly M, Kirsch J. Predictors of health-related quality of life in sufferers with restless legs syndrome: a multi-national study. Sleep Med. 2007 Jan 1;8(1):73-83.