@article{NUMA_1968__12_131853,
     author = {CHR. ZENGER},
     title = {On {Convexity} {Properties} of the {Bauer} {Field} of {Values} of a {Matrix.}},
     journal = {Numerische Mathematik},
     pages = {96--105},
     publisher = {mathdoc},
     volume = {12},
     year = {1968},
     zbl = {0182.49103},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1968__12_131853/}
}