@article{MAN_1966__163_161351,
     author = {A.E. Taylor},
     title = {Theorems on {Ascent,} {Descent,} {Nullity} and {Defect} of {Linear} {Operators.}},
     journal = {Mathematische Annalen},
     pages = {18--49},
     publisher = {mathdoc},
     volume = {163},
     year = {1966},
     zbl = {0138.07602},
     url = {http://geodesic.mathdoc.fr/item/MAN_1966__163_161351/}
}