Wechselberger, Peter, Stefan Lang, and Winfried J. Steiner. “Additive Models With Random Scaling Factors: Applications to Modeling Price Response Functions”. Austrian Journal of Statistics 37, no. 3&4 (April 3, 2016): 255–270. Accessed May 10, 2021. https://ajs.or.at/index.php/ajs/article/view/vol37%2C%20no3%264%20-%204.