diff --git a/无进位乘法和GHASH.md b/无进位乘法和GHASH.md
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 # 参考
 * [Cryptographic Hardware and Software and useful architectures](https://www.esat.kuleuven.be/cosic/events/ecrypt-net-school-2018/wp-content/uploads/sites/23/2018/10/kos-school-gueron-2.pdf)
 * [The Galois/Counter Mode of Operation (GCM)](https://csrc.nist.rip/groups/ST/toolkit/BCM/documents/proposedmodes/gcm/gcm-revised-spec.pdf)
-* Recommendation for Block 
+* [Recommendation for Block 
 Cipher Modes of Operation: 
 Galois/Counter Mode (GCM) 
-and GMAC
+and GMAC](https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf)
 * [Intel® Carry-Less 
 Multiplication 
 Instruction and its