@article{oai:tsukuba.repo.nii.ac.jp:00016249,
 author = {Umezu, Kenichiro},
 issue = {2},
 journal = {Tsukuba Journal of Mathematics},
 month = {Dec},
 pages = {275--292},
 title = {On the Cauchy problem for analytic semigroups with weak singulality},
 volume = {15},
 year = {1991}
}