diff --git a/docs/voip_signaling.md b/docs/voip_signaling.md
index ba72e1b218..c80cdd6b96 100644
--- a/docs/voip_signaling.md
+++ b/docs/voip_signaling.md
@@ -1,3 +1,7 @@
+Useful links:
+- https://codelabs.developers.google.com/codelabs/webrtc-web/#0
+
+
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    ║                                                ║
    ║A] Placing a call offer                         ║