Lallemand, V., M. Minier, and L. Rouquette. “Automatic Search of Rectangle Attacks on Feistel Ciphers: Application to WARP”. IACR Transactions on Symmetric Cryptology, vol. 2022, no. 2, June 2022, pp. 113-40, doi:10.46586/tosc.v2022.i2.113-140.