diff --git a/Diagram-support.md b/Diagram-support.md
index 0467015..189b0c6 100644
--- a/Diagram-support.md
+++ b/Diagram-support.md
@@ -29,6 +29,8 @@ usecase usecase
 @enduml
 ```
 
+See: http://plantuml.com/timing-diagram
+
 # flowchart
 ![image](https://user-images.githubusercontent.com/11307908/29246519-2d7f2032-8038-11e7-97e3-187d8aad18c4.png)