TY  - JOUR
AU  - Hidekazu Ito
TI  - Action-angle coordinates at singularities for analytic integrable systems.
JO  - Mathematische Zeitschrift
PY  - 1991
SP  - 363
EP  - 408
VL  - 206
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZ_1991__206_1_174233/
ID  - MZ_1991__206_1_174233
ER  -