@article{NUMA_1991__60_4_133604,
     author = {D. Hinrichsen and A.J. Pritchard},
     title = {On spectral variations under bounded real matrix perturbations.},
     journal = {Numerische Mathematik},
     pages = {509--524},
     publisher = {mathdoc},
     volume = {60},
     number = {4},
     year = {1991},
     zbl = {0747.65021},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1991__60_4_133604/}
}