diff --git a/README.md b/README.md
index 8e6c2f0..804ba90 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,3 @@
-# DDS_VFO
-Code for the arduino-controlled VFO based on the Si5351 chip
+Code modified from https://projecthub.arduino.cc/CesarSound/10khz-to-225mhz-vforf-generator-with-si5351-version-2-acdc25.
+
+Some related documentation at https://w1cdn.net.