G. Eskin,Paramatrix and propagation of singularities for the interior mixed hyperbolic problem, J. Analyse Math.,32 (1977), pp. 17–62.
G. Eskin,Initial-boundary value problems for second order hyperbolic equations with general boundary conditions - I, II, J. Analyse Math.,40 (1981), pp. 43–89, and Communic. in P.D.E.,10 (1985), pp. 1117–1212.
L.Hormander,The analysis of linear partial differential operators, I, II, III, IV, Springer-Verlag, 1983, 1983, 1985, 1985.
I.Lasiecka,Sharp regularity results for mixed hyperbolic problems of second order, Lectures Notes in Mathematics, 1223, Springer-Verlag, 1986.
J. L. Lions,Contrôle des systèmes distribués singuliers, Gauthier-Villars, Paris, 1983.
I.Lasiecka - R.Triggiani,A cosine operator approach to modeling L
2(Γ))boundary input hyperbolic equations, Appl. Math. & Optimiz., i (1981), pp. 35–83.
I. Lasiecka -R. Triggiani,Regularity of hyperbolic equations under L2(0,T; L
2(Γ))-boundary terms, Appl. Math. & Optimiz.,10 (1983), pp. 275–286.
I. Lasiecka -R. Triggiani,Trace regularity of the solutions of the wave equation with homogeneous Neumann boundary conditions and compactly supported data, J. Math. Anal. & Appl.,141, no. 1 (1989), pp. 49–71.
I. Lasiecka -R. Triggiani,A lifting theorem for the time regularity of solutions to abstract equations with unbounded operators and applications to hyperbolic equations, Proc. Amer. Math. Soc.,104, no. 3 (1988), pp. 745–755.
I.Lasiecka - R.Triggiani,Regularity theory of hyperbolic equations with non-homogeneous Neumann boundary conditions, Part II:General boundary data, preprint 1989.
I.Lasiecka - R.Triggiani,Differential Riccati Equations with unbounded coefficients: applications to boundary control/boundary observation hyperbolic problems, preprint 1990.
I.Lasiecka - R.Triggiani,Announcement in Atti Acc. Lincei Rend. Fis., (8), LXXXIII (1989), to appear.
I. Lasiecka -J. L. Lions -R. Triggiani,Nonhomogeneous boundary value problems for second order hyperbolic operators, J. Math. Pures et Appl.,69 (1986), pp. 149–192.
J. L.Lions - E.Magenes,Nonhomogeneous Boundary Value Problems and Applications, I, II (1972) and III (1973), Springer-Verlag.
S. Myatake,Mixed problem for hyperbolic equations of second order, J. Math. Kyoto Univ.,130, no. 3 (1973), pp. 435–487.
R. Sakamoto,Mixed problems for hyperbolic equations, I, II, J. Math. Kyoto Univ.,10, no. 2 (1970), pp. 343–373 and10, no. 3 (1970), pp. 403–417.
R.Sakamoto,Hyperbolic boundary value problems, Cambridge University Press (1982).
W. W. Symes,A trace theorem for solutions of the wave equation and the remote determination of acoustic sources, Math. Methods in the Applied Sciences,5 (1983), pp. 35–93.
M. E. Taylor,Pseudo-differential operators, Princeton University Press, Princeton, New Jersey (1981).
R.Triggiani,An announcement of sharp regularity theory for second order hyperbolic equations of Neumann type, Springer-Verlag Lecture Notes, inControl and Information Sciences,114, pp. 284–288; Proceedings IFIP Conference on optimal control for systems governed by partial differential equations, held at University of Santiago de Campostela, Spain, July 1987