@article{IM_1979__51_142635,
     author = {J. Tits},
     title = {Non-existence de certains polygones g\'en\'eralis\'es. {II.}},
     journal = {Inventiones mathematicae},
     pages = {267--270},
     publisher = {mathdoc},
     volume = {51},
     year = {1979},
     zbl = {0429.20029},
     url = {http://geodesic.mathdoc.fr/item/IM_1979__51_142635/}
}