1. Toward a more practical control theory for distributed parameter systems;Balas,1982
2. The linear regulator problem for parabolic systems;Banks;SIAM J. Contr. and Opt.,1984
3. Finite-dimensional linear systems;Brockett,1970
4. Recent advances on spectral factorization and LQ-optimal regulation for multivariable distributed systems;Callier,1991