@article{IM_1973__21_142232,
     author = {Gopal Prasad},
     title = {Strong {Rigidity} of {Q-Rank} 1 {Lattices.}},
     journal = {Inventiones mathematicae},
     pages = {255--286},
     publisher = {mathdoc},
     volume = {21},
     year = {1973},
     zbl = {0264.22009},
     url = {http://geodesic.mathdoc.fr/item/IM_1973__21_142232/}
}