diff --git a/SM4-with-AESENCLAST.md b/SM4-with-AESENCLAST.md
index 3196264..54c1117 100644
--- a/SM4-with-AESENCLAST.md
+++ b/SM4-with-AESENCLAST.md
@@ -192,5 +192,6 @@ func gen_matrix(lookup [256]byte) (m [8]byte) {
 
 # Reference
 * [AES-NI used in SM4](https://github.com/mjosaarinen/sm4ni)
+* [Advanced Encryption Standard (AES)](https://www.nist.gov/publications/advanced-encryption-standard-aes)
 * [AES 和 SM4 S盒複合域實現方法](https://ppfocus.com/0/ed0cb869b.html)
-* [Advanced Encryption Standard (AES)](https://www.nist.gov/publications/advanced-encryption-standard-aes)
\ No newline at end of file
+* [A Very Compact S-box for AES](https://www.iacr.org/archive/ches2005/032.pdf)
\ No newline at end of file