@article{10_21136_AM_1990_104417,
     author = {Kojeck\'y, Tom\'a\v{s}},
     title = {Some functions of eigenvalues of normal operator},
     journal = {Applications of Mathematics},
     pages = {356--360},
     publisher = {mathdoc},
     volume = {35},
     number = {5},
     year = {1990},
     doi = {10.21136/AM.1990.104417},
     mrnumber = {1072606},
     zbl = {0726.65059},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/articles/10.21136/AM.1990.104417/}
}