M. Akelbek, S. Kirkland: Coefficients of ergodicity and the scrambling index. Linear Algebra Appl. 430 (2009), 1111–1130.
M. Akelbek, S. Fital, J. Shen: A bound on the scrambling index of a primitive matrix using Boolean rank. Linear Algebra Appl. 431 (2009), 1923–1931.
R. A. Brualdi, H. J. Ryser: Combinatorial Matrix Theory. Encyclopedia of Mathematics and its Applications 39, Cambridge University Press, Cambridge, 1991.
B. L. Liu, L. H. You, G. X. Yu: On extremal matrices of second largest exponent by Boolean rank. Linear Algebra Appl. 422 (2007), 186–197.
Y. Shao, Y. Gao: On the second largest scrambling index of primitive matrices. Ars Comb. 113 (2014), 457–462.