diff --git a/js/event-bubbling.js b/js/event-bubbling.js
index 618a9c2..55c8369 100644
--- a/js/event-bubbling.js
+++ b/js/event-bubbling.js
@@ -3,6 +3,7 @@
  *
  * @Reference:
  * http://javascript.info/tutorial/bubbling-and-capturing
+ * https://www.sitepoint.com/event-bubbling-javascript/
  * http://stackoverflow.com/questions/4616694/what-is-event-bubbling-and-capturing
  * http://javascript.info/tutorial/mouse-events
  *