TY  - JOUR
AU  - Hidekazu Ito
TI  - Convergence of Birkhoff normal forms for integrable systems.
JO  - Commentarii mathematici Helvetici
PY  - 1989
SP  - 412
EP  - 461
VL  - 64
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMH_1989__64_1_140164/
ID  - CMH_1989__64_1_140164
ER  -