TY  - JOUR
AU  - Hsu, Leetsch C.
TI  - An estimation for the first exponential formula in the theory of semigroups of linear operations
JO  - Czechoslovak Mathematical Journal
PY  - 1960
SP  - 323
EP  - 328
VL  - 10
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1960.100416/
DO  - 10.21136/CMJ.1960.100416
LA  - en
ID  - 10_21136_CMJ_1960_100416
ER  -