TY  - JOUR
AU  - Peter Hess
AU  - Tosio Kato
TI  - Perturbation of Closed Operators and Their Adjoints.
JO  - Commentarii mathematici Helvetici
PY  - 1970
SP  - 524
EP  - 529
VL  - 45
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMH_1970__45_139455/
ID  - CMH_1970__45_139455
ER  -