1. Boundary control of parabolic equations: L-Q-R theory;Balakrishnan,1978
2. On a class of Riccati equations in a Hilbert space;Balakrishnan;Appl. Math. Optim.,1981
3. A regularity theorem for parabolic equations;Bardos;Journal of Functional Analysis,1971
4. Boundary control of parabolic systems: regularity of optimal solutions;Lasiecka;Appl. Math. Optim.,1978
5. State constraint control problems for parabolic systems: regularity of optimal solutions;Lasiecka;Appl. Math. Optim.,1980