1. Graham, Alexander. 1981. “Kronecker Products and Matrix Calculus with Application”. Ellis Horwood Limited.
2. Neuts, M. F. 1981. “Matrix-Geometric Solutions in Stochastic Models”. Baltimore and London: The Johns Hopkins University Press.
3. Neuts, M. F. July 1989. “Structured Stochastic Matrices of M/G/l Type and Their Applications”. July, New York: Marcel Dekker Inc.