4.8 OLS Reference
Penn State University, STAT 501, Lesson 12: Multicollinearity & Other Regression Pitfalls. https://newonlinecourses.science.psu.edu/stat501/lesson/12.
STHDA. Bootstrap Resampling Essentials in R. http://www.sthda.com/english/articles/38-regression-model-validation/156-bootstrap-resampling-essentials-in-r/
Molnar, Christoph. “Interpretable machine learning. A Guide for Making Black Box Models Explainable”, 2019. https://christophm.github.io/interpretable-ml-book/.