1. “The Relationship of Alternate State-Space Representations in Linear Filtering Problems,”;Athans;IEEE Trans. Automatic Control,1967
2. Finite Dimensional Linear Systems;Brockett,1970
3. Introduction to Linear System Theory;Chen,1970
4. Theory of Ordinary Differential Equations;Coddington,1955
5. Linear Control Systems Analysis anil Design: Conventional and Modern;D'Azzo,1975