@article{GDZPPN002098644,
title = {On the Variation in the Cohomology of the Symplectic Form of the Reduced Phase Space.},
journal = {Inventiones mathematicae},
volume = {69},
year = {1982},
pages = {259-268},
zbl = {0503.58015},
url = {http://dml.mathdoc.fr/item/GDZPPN002098644}
}
Duistermaat, J.J.; Heckman, G.J. On the Variation in the Cohomology of the Symplectic Form of the Reduced Phase Space.. Inventiones mathematicae, Tome 69 (1982) pp. 259-268. http://gdmltest.u-ga.fr/item/GDZPPN002098644/