@article{SF_1987__36_134909,
     author = {J.M. Day and D.D. Weddington},
     title = {Some conditions under which a continuous semigroup morphism is strongly differentiable.},
     journal = {Semigroup forum},
     pages = {371--374},
     publisher = {mathdoc},
     volume = {36},
     year = {1987},
     zbl = {0632.22004},
     url = {http://geodesic.mathdoc.fr/item/SF_1987__36_134909/}
}