The Elements of Statistical Learning

by Trevor Hastie, Robert Tibshirani, Jerome Friedman

Forecasting: principles and practice

by Rob J Hyndman, George Athanasopoulos

An Introduction to R

by W. N. Venables, D. M. Smith, R Development Core Team

The R Inferno

by Patrick Burns

Advanced R Programming

by Hadley Wickham

r

R for Data Science

by Garrett Grolemund, Hadley Wickham