@article{MZ_1989__201_4_174039,
     author = {Mats Andersson},
     title = {The {Corona} {Theorem} for {Matrices.}},
     journal = {Mathematische Zeitschrift},
     pages = {121--130},
     publisher = {mathdoc},
     volume = {201},
     number = {4},
     year = {1989},
     zbl = {0648.30039},
     url = {http://geodesic.mathdoc.fr/item/MZ_1989__201_4_174039/}
}