@article{GDZPPN001168363, title = {Nested Bounds for the Spectral Radius.}, journal = {Numerische Mathematik}, volume = {15}, year = {1970}, pages = {49-70}, zbl = {0221.65063}, url = {http://dml.mathdoc.fr/item/GDZPPN001168363} }
VARGA, R.S.; MAREK, I. Nested Bounds for the Spectral Radius.. Numerische Mathematik, Tome 15 (1970) pp. 49-70. http://gdmltest.u-ga.fr/item/GDZPPN001168363/