References
- Proc. London Math. Soc v.55 TheCauchy problem and a generalization of the Hille Yosida theorem E.B.Davies;M. M. H. Pang
- Proc. Nat. Acad. Sc. U. S. A. v.28 Representation of oneparameter semigroups of linear transformations E. Hille
- J. Funct. Anal v.111 Csemigroups and the Cauchy problem R. deLaubenfels
- Semigroup of linear operators and applications J. A. Goldstein
- Semigroups of linear operators and applications to partial differential equations A. Pazy