@article{CMUC_1991__32_4_a13,
     author = {So{\l}tysiak, Andrzej},
     title = {On a certain class of subspectra},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {715--721},
     publisher = {mathdoc},
     volume = {32},
     number = {4},
     year = {1991},
     mrnumber = {1159818},
     zbl = {0763.46037},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1991__32_4_a13/}
}