diff --git a/pages/audio.bluetooth.md b/pages/audio.bluetooth.md
index e76f93b..986d025 100644
--- a/pages/audio.bluetooth.md
+++ b/pages/audio.bluetooth.md
@@ -1,5 +1,6 @@
 # BT
 - BT5 is must-have
+	- https://www.howtogeek.com/343718/whats-different-in-bluetooth-5.0/
 - APTX low latency also
 # APTX
 ## windows