1. A.Bachelot, V. Petkov, Existence des opérateurs d’ondes pour les systèmes hyperboliques avec un potentiel périodique en temps, Ann.Inst. Henry Poinearé. Phys. Theor. 47 (1987), 383–428.
2. F.Cardoso and V. Petkov, Leading singularity of the scattering kernel for moving obstacles with dissipâtive boundary condition, preprint, Univ. de Pernambuco, Recife, Brazil, 1988.
3. J.Cooper, Scattering of plane waves by a moving obstacle, Arch. Rat. Mech. Anal. 71 (1979), 113–149.
4. J.Cooper and W.Strauss, Representation of the scattering operator for moving obstacles, Indiana Univ. Math. J. 28 (1979), 643–671.
5. J.Cooper and W.Strauss, Scattering of waves by periodically moving bodies, J. Funct. Anal. 47 (1982), 180–229.