diff --git a/Build-on-Linux.md b/Build-on-Linux.md
index 1cdf5ac..db16fed 100644
--- a/Build-on-Linux.md
+++ b/Build-on-Linux.md
@@ -10,4 +10,7 @@ Build on Linux
 cargo install --path . --no-default-features --features smartcard --features decrypt
 ```
 
+<br><br>
+
+> Reference: https://codeberg.org/openpgp-card/openpgp-card-tools