@article{GDZPPN001170198, title = {Inclusion Theorems for a Section of a Matrix.}, journal = {Numerische Mathematik}, volume = {18}, year = {1971}, pages = {457-464}, zbl = {0245.15003}, url = {http://dml.mathdoc.fr/item/GDZPPN001170198} }
Morris, Wm.L. Inclusion Theorems for a Section of a Matrix.. Numerische Mathematik, Tome 18 (1971) pp. 457-464. http://gdmltest.u-ga.fr/item/GDZPPN001170198/