Free R Book Collection

I have just encountered some R PDF books that seem quite interesting. One of them is written by Venables himself.

• The Art of R Programming by Norman Matloff
  
• An Introduction to R by W.N. Venables and D. M. Smith
  
• The R Inferno by Patrick Burns
  
• The R Guide by W. J. Owen
  
• R for Beginners by Emmanuel Paradis

Do you have any other suggestions I should add to the list?