@article{AUPO_1984__23_1_a9,
     author = {\v{S}t\v{e}rbov\'a, Dina},
     title = {Square roots of elements with an unbounded spectrum},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {103--106},
     publisher = {mathdoc},
     volume = {23},
     number = {1},
     year = {1984},
     mrnumber = {837033},
     zbl = {0603.46054},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_1984__23_1_a9/}
}