Fix link to book recommendation.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1933423 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/docs/manual/rewrite/intro.xml b/docs/manual/rewrite/intro.xml
index d45ac0afb846009a2eb1f4d765ccb558b1764629..46179d441b8f7b8738cf1773784656ec87a4ee53 100644 (file)
--- a/docs/manual/rewrite/intro.xml
+++ b/docs/manual/rewrite/intro.xml
@@ -79,8 +79,10 @@ to provide a detailed reference to regular expressions. For that, we
 recommend the <a href="http://pcre.org/pcre.txt">PCRE man pages</a>, the
 <a href="http://perldoc.perl.org/perlre.html">Perl regular
 expression man page</a>, and <a
-href="http://shop.oreilly.com/product/9780596528126.do">Mastering
-Regular Expressions, by Jeffrey Friedl</a>.</p>
+href="https://www.oreilly.com/library/view/mastering-regular-expressions/0596528124/">Mastering
+Regular Expressions, by Jeffrey Friedl</a> (the third edition is from
+2006, but regular expression syntax is essentially unchanged, and this
+remains the definitive reference on the subject).</p>
 
 <p>In this document, we attempt to provide enough of a regex vocabulary
 to get you started, without being overwhelming, in the hope that