@article{ARM_1994_30_1_a5,
     author = {Kowalski, Old\v{r}ich and Pr\"ufer, Friedbert},
     title = {Curvature tensors in dimension four which do not belong to any curvature homogeneous space},
     journal = {Archivum mathematicum},
     pages = {45--57},
     year = {1994},
     volume = {30},
     number = {1},
     mrnumber = {1282112},
     zbl = {0813.53027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1994_30_1_a5/}
}