@article{CMH_1979__54_139788,
     author = {P. de de Harpe},
     title = {Simplicity of the projective unitary groups defined by simple factors.},
     journal = {Commentarii mathematici Helvetici},
     pages = {334--346},
     publisher = {mathdoc},
     volume = {54},
     year = {1979},
     zbl = {0406.46051},
     url = {http://geodesic.mathdoc.fr/item/CMH_1979__54_139788/}
}