@article{IM_1972__16_142143,
     author = {Alan Weinstein},
     title = {The {Invariance} of {Poincar\'e's} {Generating} {Function} for {Canonical} {Transformations.}},
     journal = {Inventiones mathematicae},
     pages = {202--213},
     publisher = {mathdoc},
     volume = {16},
     year = {1972},
     zbl = {0235.70008},
     url = {http://geodesic.mathdoc.fr/item/IM_1972__16_142143/}
}