TY  - JOUR
AU  - Celso Martínez
AU  - Miguel Sanz
TI  - N-th roots of a non-negative operator: conditions for uniqueness.
JO  - Manuscripta mathematica
PY  - 1989
SP  - 403
EP  - 418
VL  - 64
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MM2_1989__64_2_155415/
ID  - MM2_1989__64_2_155415
ER  -