diff --git a/index.html b/index.html
index 93eff8b..a1e0ebe 100644
--- a/index.html
+++ b/index.html
@@ -22,7 +22,8 @@ An <em>IEEE Software</em> article titled
 <a href="../../pubs/jrnl/2003-IEEESW-umlgraph/html/article.html">On the declarative specification of models</a>
 explains the rationale behind this approach.
 The tehnology behind UMLGraph was used to draw many of the diagrams
-appearing in the book
+appearing in the books
+<a href="http://www.spinellis.gr/codequality">Code Quality: The Open Source Perspective</a> (Addison Wesley, 2006) and
 <a href="http://www.spinellis.gr/codereading">Code Reading: The Open Source Perspective</a> (Addison Wesley, 2003).
 In addition,
 <a href="http://lightuml.sourceforge.net/">LightUML</a>
diff --git a/web/index.html b/web/index.html
index 93eff8b..a1e0ebe 100644
--- a/web/index.html
+++ b/web/index.html
@@ -22,7 +22,8 @@ An <em>IEEE Software</em> article titled
 <a href="../../pubs/jrnl/2003-IEEESW-umlgraph/html/article.html">On the declarative specification of models</a>
 explains the rationale behind this approach.
 The tehnology behind UMLGraph was used to draw many of the diagrams
-appearing in the book
+appearing in the books
+<a href="http://www.spinellis.gr/codequality">Code Quality: The Open Source Perspective</a> (Addison Wesley, 2006) and
 <a href="http://www.spinellis.gr/codereading">Code Reading: The Open Source Perspective</a> (Addison Wesley, 2003).
 In addition,
 <a href="http://lightuml.sourceforge.net/">LightUML</a>