Add link to the website of Benedikt Nießen's book "Der eigene Server mit FreeBSD 9".

diff --git a/activities.mdwn b/activities.mdwn
index 0f52825..e69b02d 100644 (file)
--- a/activities.mdwn
+++ b/activities.mdwn
@@ -64,8 +64,11 @@ Articles we have published:
 * [Linux Magazine](http://www.linuxmag.nl/), year 1, issue 2:
   *"Virtual Private Networks met tinc"* (Dutch).
 
-References to tinc that can be found in other articles:
+References to tinc that can be found in other articles and books:
 
+* [Der eigene Server mit FreeBSD 9](http://serverzeit.de/das-buch/),
+  a book by Benedikt Nießen,
+  published in 2012 by dpunkt.verlag GmbH, ISBN: 978-3-89864-814-1.
 * [c't magazin](http://www.heise.de/ct/), 2009, issue 19:
   *"[Maschen-VPN](http://www.heise.de/ct/inhalt/2009/19/176/)"* (German).
   The full article can be read [online at heise.de](http://www.heise.de/netze/Dezentrales-VPN-mit-Tinc--/artikel/145795).