@article{IM2_1992_38_3_a9,
     author = {A. G. Sergeev and P. Heinzner},
     title = {The extended matrix disk is a domain of holomorphy},
     journal = {Izvestiya. Mathematics},
     pages = {637--645},
     year = {1992},
     volume = {38},
     number = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1992_38_3_a9/}
}