@article{1259943307,
author = {GUSTAFSON, Karl and SATO, Ken-iti},
title = {Some perturbation theorems for nonnegative contraction semigroups*},
journal = {J. Math. Soc. Japan},
volume = {21},
number = {2},
year = {1969},
pages = { 200-204},
language = {en},
url = {http://dml.mathdoc.fr/item/1259943307}
}
GUSTAFSON, Karl; SATO, Ken-iti. Some perturbation theorems for nonnegative contraction semigroups*. J. Math. Soc. Japan, Tome 21 (1969) no. 2, pp. 200-204. http://gdmltest.u-ga.fr/item/1259943307/