@article{1195522284, author = {Yosida, K\^osaku}, title = {A perturbation theorem for semi-groups of linear operators}, journal = {Proc. Japan Acad.}, volume = {41}, number = {9}, year = {1965}, pages = { 645-647}, language = {en}, url = {http://dml.mathdoc.fr/item/1195522284} }
Yosida, Kôsaku. A perturbation theorem for semi-groups of linear operators. Proc. Japan Acad., Tome 41 (1965) no. 9, pp. 645-647. http://gdmltest.u-ga.fr/item/1195522284/