--- a/udev.rst	Tue Feb 04 11:12:27 2014 +0200
+++ b/udev.rst	Tue Feb 04 23:29:05 2014 +0200
@@ -12,6 +12,15 @@
  * http://reactivated.net/writing_udev_rules.html
  * http://wiki.debian.org/udev
  * https://wiki.archlinux.org/index.php/Udev
+ * http://wiki.gentoo.org/wiki/Udev
+ * http://www.crashcourse.ca/wiki/index.php/Udev
+
+Record udev events.
+===================
+
+This dump udev events to console::
+
+  $ sudo udevadm monitor
 
 View device capability with udev compatible format.
 ===================================================
@@ -25,3 +34,10 @@
 
   $ udevinfo -a -p $(udevinfo -q path -n /dev/sdc)
 
+Debugging udev rule.
+====================
+::
+
+  $ sudo udevadm trigger
+  $ sudo udevadm test $(udevadm info -n /dev/$DEV -q path)
+