References

1. Kohavi, R. (1995). A Study of Cross-Validation and Bootstrap for Accuracy Estimation and Model Selection.
   Link to Paper

2. Hastie, T., Tibshirani, R., & Friedman, J. (2009). The Elements of Statistical Learning.

3. Kuhn, M., & Johnson, K. (2013). Applied Predictive Modeling.
   Link to Book

4. Caret Package Documentation:
   Caret Documentation