diff --git a/README.md b/README.md
index 5cbd8d6..717cb7e 100644
--- a/README.md
+++ b/README.md
@@ -4,3 +4,4 @@ Yubikey Book.
 
 
 1. https://git.hatter.ink/collect/yubikey-handbook
+1. https://github.com/drduh/YubiKey-Guide