1. Bensoussan, A. “Filtrage Optimal des Systems Lineaires,” Dunod 1971.
2. Curtain R.F. and Falb P.L. Stochastic Differential Equations in a Hilbert Space J. Diff Eqns 10 (1971) 412 – 430.
3. Curtain R.F. On the Itô Stochastic Integral in a Hilbert Space.Control Theory Centre Report No. 11, University of Warwick, England.
4. Curtain R.F. Infinite Dimensional Filtering. Siam. J. Control 13 (1975).
5. Curtain R.F. The Infinite Dimensional Riccati Equation with Applications to Affine Hereditary Differential Systems.Control Theory Centre Report No 24. University of Warwick, England. (Submitted to Siam J. Control).