Azzalini, Adelchi, and Giovanna Menardi. “Clustering via Nonparametric Density Estimation: The R Package PdfCluster”. Journal of Statistical Software 57, no. 11 (May 6, 2014): 1–26. Accessed April 23, 2024. https://www.jstatsoft.org/index.php/jss/article/view/v057i11.