@article{CMUC_1978__19_3_a2,
     author = {Pt\'ak, Vlastimil},
     title = {An infinite companion matrix},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {447--458},
     publisher = {mathdoc},
     volume = {19},
     number = {3},
     year = {1978},
     mrnumber = {508953},
     zbl = {0404.15009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1978__19_3_a2/}
}