diff --git a/common/board/esplan_ethernet.yaml b/common/board/esplan_ethernet.yaml
index 439cab4..906ef89 100644
--- a/common/board/esplan_ethernet.yaml
+++ b/common/board/esplan_ethernet.yaml
@@ -1,3 +1,6 @@
+# https://www.laskakit.cz/laskakit-esplan-esp32-lan8720a-max485-poe/?variantId=12167
+# https://github.com/LaskaKit/ESPlan
+
 esp32:
   board: esp32dev
   framework: