Epskamp, Sacha, Angélique O.J. Cramer, Lourens J. Waldorp, Verena D. Schmittmann, and Denny Borsboom. “Qgraph: Network Visualizations of Relationships in Psychometric Data”. Journal of Statistical Software 48, no. 4 (May 24, 2012): 1–18. Accessed October 18, 2021. https://www.jstatsoft.org/index.php/jss/article/view/v048i04.