Ünlü, Ali, Thomas Kiefer, and Ehtibar N. Dzhafarov. “Fechnerian Scaling in R: The Package Fechner”. Journal of Statistical Software 31, no. 6 (August 10, 2009): 1–24. Accessed April 19, 2024. https://www.jstatsoft.org/index.php/jss/article/view/v031i06.