@article{MZ_1981__178_173105,
     author = {Donald G. James},
     title = {Homomorphisms of {Unitary} {Groups.}},
     journal = {Mathematische Zeitschrift},
     pages = {343--352},
     year = {1981},
     volume = {178},
     zbl = {0451.20042},
     url = {http://geodesic.mathdoc.fr/item/MZ_1981__178_173105/}
}