1. Introduction to stochastic control;Åström,1970
2. Aloisi P. and Bertin, D. (1984). Thesis, Politecnico di Milano, Italy.
3. Bertin D., S. Bittanti and P. Bolzern (1985). 4th International Conference of Systems Engineering, Conventry, U.K.
4. Factorization methods for discrete system estimation;Bierman,1977