diff --git a/lkmpg.tex b/lkmpg.tex
index 31fa257..0cd0aa8 100644
--- a/lkmpg.tex
+++ b/lkmpg.tex
@@ -648,7 +648,7 @@ The file \verb|/proc/kallsyms| holds all the symbols that the kernel knows about
 
 \subsection{Code space}
 \label{sec:codespace}
-Memory management is a very complicated subject and the majority of O'Reilly's "\emph{Understanding The Linux Kernel}" exclusively covers memory management!
+Memory management is a very complicated subject and the majority of O'Reilly's \href{https://www.oreilly.com/library/view/understanding-the-linux/0596005652/}{Understanding The Linux Kernel} exclusively covers memory management!
 We are not setting out to be experts on memory managements, but we do need to know a couple of facts to even begin worrying about writing real modules.
 
 If you have not thought about what a segfault really means, you may be surprised to hear that pointers do not actually point to memory locations.