diff --git a/ciphers/a1z26_cipher.cpp b/ciphers/a1z26_cipher.cpp
index dda21e757..06526d409 100644
--- a/ciphers/a1z26_cipher.cpp
+++ b/ciphers/a1z26_cipher.cpp
@@ -24,7 +24,7 @@
 namespace ciphers {
 /**
  * @namespace a1z26
- * @brief Functions for [A1Z26] encryption and decryption implementation
+ * @brief Functions for [A1Z26](https://www.dcode.fr/letter-number-cipher) encryption and decryption implementation
  */
 namespace a1z26 {