@article{ELMA_1972__27_141071,
     author = {Fritz Hohenberg},
     title = {Die {Polarit\"aten,} die einen {Torus} in sich \"uberf\"uhren.},
     journal = {Elemente der Mathematik},
     pages = {97--101},
     publisher = {mathdoc},
     volume = {27},
     year = {1972},
     zbl = {0222.50009},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1972__27_141071/}
}