1. Banks, H.T., Kunisch, K.: The linear regulator problem for parabolic systems. SIAM J. Control Opt. 22, 684–698 (1984)
2. Banks, H.T., Keeling, S.L., Silcox, R.J.: Optimal control techniques for active noise suppression, In: Proceedings 27th IEEE Conference on Dec. and Control, Austin, pp. 2006–2011 (1988)
3. Banks, H.T., Wang, C.: Optimal feedback control of infinite-dimensional parabolic evolution systems: approximation techniques. SIAM J. Control Optim. 27, 1182–1219 (1989)
4. Banks, H.T., Propst, G., Silcox, R.J.: A comparison of time domain boundary conditons for acoustic waves in wave guides, ICASE Rep. No. 91–27, NASA Langly Res. Ctr , Hampton, VA (1991)
5. Bardos, C., Lebeau, G., Rauch, J.: Sharp sufficient conditions for the observation, control, and stabilization of waves from the boundary. SIAM J. Control Opt. 30, 1024–1065 (1992)