@article{MZ_1972__125_171713,
     author = {Birger Iversen},
     title = {On the {Exceptional} {Tangents} to a {Smooth,} {Plane} {Curve.}},
     journal = {Mathematische Zeitschrift},
     pages = {359--360},
     publisher = {mathdoc},
     volume = {125},
     year = {1972},
     zbl = {0232.14012},
     url = {http://geodesic.mathdoc.fr/item/MZ_1972__125_171713/}
}