@article{10_1090_S0894_0347_98_00258_6,
     author = {Becker, Howard},
     title = {Polish group actions: {Dichotomies} and generalized elementary embeddings},
     journal = {Journal of the American Mathematical Society},
     pages = {397--449},
     publisher = {mathdoc},
     volume = {11},
     number = {2},
     year = {1998},
     doi = {10.1090/S0894-0347-98-00258-6},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-98-00258-6/}
}