@article{10_21136_CMJ_1973_101203,
     author = {Pt\'ak, Vlastimil and Vrbov\'a, Pavla},
     title = {On the spectral function of a normal operator},
     journal = {Czechoslovak Mathematical Journal},
     pages = {615--616},
     publisher = {mathdoc},
     volume = {23},
     number = {4},
     year = {1973},
     doi = {10.21136/CMJ.1973.101203},
     mrnumber = {0336421},
     zbl = {0268.47025},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/articles/10.21136/CMJ.1973.101203/}
}