@article{PORMA_1985__43_1_114545,
     author = {Elsner, L.},
     title = {Perturbation theorems for the matrix eigenvalue problem},
     journal = {Portugaliae mathematica},
     pages = {69--76},
     publisher = {mathdoc},
     volume = {43},
     number = {1},
     year = {1985},
     mrnumber = {0875054},
     zbl = {0579.15007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1985__43_1_114545/}
}