@article{ERAAMS_1996_02_3_a2,
     author = {Katok, A. and Spatzier, R.},
     title = {Nonstationary normal forms and rigidity of group actions},
     journal = {Electronic research announcements of the American Mathematical Society},
     pages = {124--133},
     publisher = {mathdoc},
     volume = {02},
     number = {3},
     year = {1996},
     doi = {10.1090/S1079-6762-96-00016-9},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S1079-6762-96-00016-9/}
}