1. State-Space and Multivariable Theory;Rosenbrock,1970
2. Linear Optimal Control Systems;Kwakernaak,1972
3. Structural invariants of linear multivariable systems;Morse;SIAM J. Control,1973
4. Canonical Forms of Linear Multivariable Systems;Wang,1972
5. Equivalent characterizations of zeros in multivariable systems;Moore,1972