• Advanced R Programming - Hadley Wickham
• Introduction to Probability and Statistics Using R - G. Jay Kerns (PDF)
• Learning Statistics with R - Daniel Navarro
• learnR - (Work in Progress) - Kun Ren
• Practical Regression and Anova using R - Julian J. Faraway (PDF)
• R for spatial analysis (PDF)
• R language for Programmers - John D. Cook
• R packages - Hadley Wickham
• R practicals (PDF)
• R Programming
• R Programming for Data Science (Needs valid email)
• R Succinctly, Syncfusion (PDF, Kindle) (Just fill the fields with any values)
• The R Inferno - Patrick Burns (PDF)
• The R Language
• The R Manuals