diff --git a/dont_fret/channel_kde.py b/dont_fret/channel_kde.py
index f91d91b..95ab18f 100644
--- a/dont_fret/channel_kde.py
+++ b/dont_fret/channel_kde.py
@@ -7,6 +7,9 @@
 
 Please cite the paper when using this module.
 
+See also:
+https://nbviewer.org/github/OpenSMFS/FRETBursts_notebooks/blob/master/notebooks/Example%20-%202CDE%20Method.ipynb
+
 """
 
 import warnings