1. Quantum Mechanics;Schiff,1955
2. Quantum Mechanics in Hilbert Space;Prugovecki,1971
3. A.N. Tichonov, V.Y. Arsenin, Solution of Ill-Posed Problems, Willey, London, 1977 (English Translation)
4. Optimal Control of Systems Governed by Partial Differential Equations;Lions,1971
5. O.A. Ladyzhenskaya, V.A. Soloninkov, N.N. Ural'tseva, Linear and Quasilinear Equations of Parabolic Type, Nauka, Moscow, 1967, AMS, Providence, RI, 1968, English Translation