@article{MAN_1994__299_4_165213,
     author = {Michael Kapovich},
     title = {Deformations of representations of discrete subgroups of {SO} (3,1).},
     journal = {Mathematische Annalen},
     pages = {341--354},
     publisher = {mathdoc},
     volume = {299},
     number = {4},
     year = {1994},
     zbl = {0828.57009},
     url = {http://geodesic.mathdoc.fr/item/MAN_1994__299_4_165213/}
}