@article{JOLT_2009_19_2_a3,
     author = {Cornelia Vizman},
     title = {Central {Extensions} of {Coverings} of {Symplectomorphism} {Groups}},
     journal = {Journal of Lie Theory},
     pages = {237--249},
     year = {2009},
     volume = {19},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/JOLT_2009_19_2_a3/}
}