1. The matrix minimum prin-ciple;Athans;Information and Control,1968
2. Optimal constant controllers for stochastic linear systems;Basuthakur;IEEE Trans. Automatic Control,1975
3. On calculating gradient matrices;Ceering;IEEE Trans. Automatic Control,1976
4. Modern Control System Theory;Gopal,1984
5. Solution of the optimal constant output feedback problem by conjuqate gradients;Horisberger;IEEE Trans. Automatic Control,1974