Bogdanov, A., E. Tischhauser, and P. Vejre. “Multivariate Profiling of Hulls for Linear Cryptanalysis”. IACR Transactions on Symmetric Cryptology, Vol. 2018, no. 1, Mar. 2018, pp. 101-25, doi:10.13154/tosc.v2018.i1.101-125.