1. R. Anderson, E. Biham, L. Knudsen, Serpent: A Proposal for the AES, 1st AES Conference, 1998.
2. Lect Notes Comput Sci;E. Biham,2000
3. Lect Notes Comput Sci;J. Daemen,1997
4. V. Rijmen, J. Daemen, AES Proposal: Rijndael, 1st AES Conference, 1998.