diff --git a/cookbook/coeditions.php b/cookbook/coeditions.php
index 312275f..4c78d49 100644
--- a/cookbook/coeditions.php
+++ b/cookbook/coeditions.php
@@ -1,6 +1,7 @@
 <?php
 
 # return coeditions for a wholewiki
+# http://fabien.benetou.fr/MemoryRecalls/ImprovingPIM#TimelyCoeditions
 
 function Coeditions($groupname){