diff --git a/books.md b/books.md
index 9effa54..0881731 100644
--- a/books.md
+++ b/books.md
@@ -74,7 +74,7 @@ The following is a list of free, open source books on machine learning, statisti
 * [Introduction to Probability](http://athenasc.com/probbook.html) -  Book and course by MIT
 * [The Elements of Statistical Learning: Data Mining, Inference, and Prediction.](http://statweb.stanford.edu/~tibs/ElemStatLearn/) - Book
 * [An Introduction to Statistical Learning with Applications in R](http://www-bcf.usc.edu/~gareth/ISL/) - Book
-* [Introduction to Probability and Statistics Using R](https://cran.r-project.org/web/packages/IPSUR/vignettes/IPSUR.pdf) - Book
+* [Introduction to Probability and Statistics Using R](http://ipsur.r-forge.r-project.org/book/download/IPSUR.pdf) - Book
 * [Advanced R Programming](http://adv-r.had.co.nz) - Book
 * [Practical Regression and Anova using R](http://cran.r-project.org/doc/contrib/Faraway-PRA.pdf) - Book
 * [R practicals](http://www.columbia.edu/~cjd11/charles_dimaggio/DIRE/resources/R/practicalsBookNoAns.pdf) - Book