@article{NUMA_1991__59_8_133554,
     author = {C. Carstensen},
     title = {Inclusion of the roots of a polynomial based on {Gerschgorin's} theorem.},
     journal = {Numerische Mathematik},
     pages = {349--360},
     publisher = {mathdoc},
     volume = {59},
     number = {8},
     year = {1991},
     zbl = {0726.65053},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1991__59_8_133554/}
}