@article{ELMA_1995__50_4_141579,
     author = {Christian Okonek},
     title = {Die vierte {Dimension.}},
     journal = {Elemente der Mathematik},
     pages = {107--115},
     publisher = {mathdoc},
     volume = {50},
     number = {4},
     year = {1995},
     zbl = {0859.57021},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1995__50_4_141579/}
}