@article{MAN_1935__110_159724,
     author = {I. Johansson},
     title = {\"Uber singul\"are {Elementarfl\"achen} und das {Dehnsche} {Lemma.}},
     journal = {Mathematische Annalen},
     pages = {312--320},
     publisher = {mathdoc},
     volume = {110},
     year = {1935},
     zbl = {60.0517.04},
     url = {http://geodesic.mathdoc.fr/item/MAN_1935__110_159724/}
}