@article{MZ_1976__150_172406,
     author = {Fritz Peter Harth},
     title = {Zur {Regularit\"at} von {H-Fl\"achen} mit freiem {Rand.}},
     journal = {Mathematische Zeitschrift},
     pages = {71--74},
     year = {1976},
     volume = {150},
     zbl = {0352.53004},
     url = {http://geodesic.mathdoc.fr/item/MZ_1976__150_172406/}
}