@article{MOMA_1971__75_177567,
     author = {Walter Wunderlich},
     title = {Kurven mit isotopischer {Ellipse.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {346--362},
     publisher = {mathdoc},
     volume = {75},
     year = {1971},
     zbl = {0223.53003},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1971__75_177567/}
}