1. Strongly Continuous Semigroup, Weak Solution, and the Variation of Constants Formula;Ball;Proc. Amer. Soc.,1977
2. Bank H. T. & Kunisch K., LCDS Report 81–7, 4 (1981).
3. Applied Functional Analysis;Balakrishnan,1976
4. Infinite Dimensional Linear Systems Theory;Curtain,1978
5. Time Optimal Boundary Control for Systems governed by Parablic Equations;Xunjing;Chinese Annals of Mathematics,1980