@article{MZ_1988__200_3_174027,
     author = {Richard Gabriel},
     title = {Zur besten normalen {Approximation} komplexer {Matrizen} in der {Euklidischen} {Norm.}},
     journal = {Mathematische Zeitschrift},
     pages = {591--600},
     publisher = {mathdoc},
     volume = {200},
     number = {3},
     year = {1988},
     zbl = {0648.15018},
     url = {http://geodesic.mathdoc.fr/item/MZ_1988__200_3_174027/}
}