@article{10_21136_CMJ_1969_100901,
     author = {N\'aden{\'\i}k, Zbyn\v{e}k},
     title = {\"Uber die {Enveloppe} von {Zylinderfl\"achen} konstanter {Breite}},
     journal = {Czechoslovak Mathematical Journal},
     pages = {349--355},
     publisher = {mathdoc},
     volume = {19},
     number = {2},
     year = {1969},
     doi = {10.21136/CMJ.1969.100901},
     mrnumber = {0248692},
     zbl = {0181.49202},
     language = {ge},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1969.100901/}
}