Bogdanov, Andrey, Elmar Tischhauser, and Philip Vejre. “Multivariate Profiling of Hulls for Linear Cryptanalysis”. IACR Transactions on Symmetric Cryptology 2018, no. 1 (March 1, 2018): 101-125. Accessed July 17, 2019. https://tosc.iacr.org/index.php/ToSC/article/view/846.