A Note on G-Generating Families and Isolated Gerschgorin Disks. H.I. Medley — 1973 Numerische Mathematik
On Smallest Isolated Gerschgorin Disks for Eigenvalues. II. R.S. VARGA; H.I. MEDLEY — 1968 Numerische Mathematik
On Smallest Isolated Gerschgorin Disks for Eigenvalues. III. R.S. VARGA; H.I. MEDLEY — 1968 Numerische Mathematik