@article{CMUC_1967__8_4_a2,
     author = {Kowalski, Old\v{r}ich},
     title = {The invariant classification of 3-dimensional linear subspaces of infinitesimal isometries of $E_3$},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {635--649},
     publisher = {mathdoc},
     volume = {08},
     number = {4},
     year = {1967},
     mrnumber = {0228629},
     zbl = {0163.43003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1967__8_4_a2/}
}