diff --git a/README.md b/README.md
index dfb56f4..8749eeb 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,7 @@ RadiationD-v1.1(CAJOE):
 * deep_sleep (connect D0 to RST)
 * https://hackaday.com/2014/10/25/use-a-cheap-pin-diode-as-a-geiger-counter/ (opengeiger.de/elektronik.html)
 * Solar power
+* https://odlinfo.bfs.de/DE/aktuelles/messstelle/051130004.html
 
 ## License