@article{NUMA_1970__14_131942,
     author = {R.S. VARGA and I. MAREK},
     title = {Nested {Bounds} for the {Spectral} {Radius.}},
     journal = {Numerische Mathematik},
     pages = {49--70},
     publisher = {mathdoc},
     volume = {14},
     year = {1970},
     zbl = {0221.65063},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1970__14_131942/}
}