@article{GDZPPN001169440,
title = {A Note on a Paper of Johnston and Smith's Concerning Best Isolated Gerschgorin Disks.},
journal = {Numerische Mathematik},
volume = {15},
year = {1970},
pages = {435-441},
zbl = {0198.20901},
url = {http://dml.mathdoc.fr/item/GDZPPN001169440}
}
MEDLEY, H.L. A Note on a Paper of Johnston and Smith's Concerning Best Isolated Gerschgorin Disks.. Numerische Mathematik, Tome 15 (1970) pp. 435-441. http://gdmltest.u-ga.fr/item/GDZPPN001169440/