G. Beauchamp: Algorithms for Singular Systems. Ph. D. Thesis, School of Electrical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, 1990.
 S. L. Campbell: Comments on 2-D descriptor systems. Proc. IFAC Workshop on System Structure and Control: State-Space and Polynomial Methods, pp. 249-252, Prague, Sept. 1989.
 T. Kaczorek: Existence and uniqueness of solutions and Cayley-Hamilton theorem for general singular model of 2-D systems. Electronics and Electrotechnics, Accademia Polacca della Scienze, Vicolo Doria 2, 03-187 Roma, 1988.
 T. Kaczorek: Solvability of the singular Fornasini-Marchesini's model and its reduction to an equivalent 1-D model with variable structure. Electronics and Electrotechnics, Accade- mia Polacca della Scienze, Vicolo Doria 2, 00-187 Roma, 1988.
 D. G. Luenberger: Time-invariant descriptor systems
. Automatica 14 (1978), 473 - 480. Zbl 0398.93040
 W. Marszalek: Two-dimensional state-space discrete models for hyperbolic partial differential equations
. Appl. Math. Modeling 8 (1984), 11-14. MR 0734035
| Zbl 0529.65039
 R. P. Roesser: A discrete state-space model for linear image processing
. IEEE Trans. Automat. Control AC-20 (1975), 1-10. Dr. Gerson Beauchamp, Electrical and Computer Engineering Department, University of Puerto MR 0434507
| Zbl 0304.68099