Kalisch, Markus, Martin Mächler, Diego Colombo, Marloes H. Maathuis, and Peter Bühlmann. “Causal Inference Using Graphical Models With the R Package Pcalg”. Journal of Statistical Software 47, no. 11 (May 17, 2012): 1–26. Accessed July 4, 2022. https://www.jstatsoft.org/index.php/jss/article/view/v047i11.