diff --git a/README.md b/README.md
index cfb6932..8e1dbd2 100644
--- a/README.md
+++ b/README.md
@@ -80,4 +80,5 @@ these networks.
 # Usefull links
 
 https://en.wikipedia.org/wiki/Reserved_IP_addresses
-https://www.ipaddressguide.com/a
+
+https://www.ipaddressguide.com/cidr