diff --git a/README.md b/README.md
index 7128ae4..2a78abb 100644
--- a/README.md
+++ b/README.md
@@ -92,7 +92,7 @@ StandMapHom.py:
 	Homoclinic tangle for the standard map.
 
 StandMapTwist.py: 
-	The Standard Map in twist format
+	The Standard Map in twist format  (See: https://galileo-unbound.blog/2019/10/14/how-number-theory-protects-you-from-the-chaos-of-the-cosmos/)
 
 trirep.py: 
 	Replicator dynamics in 3D simplex format.