@article{MOMA_1985__99_178211,
     author = {H. Hagen},
     title = {Minding-Isometrien bei (k + {1)-Regelfl\"achen.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {29--36},
     publisher = {mathdoc},
     volume = {99},
     year = {1985},
     zbl = {0553.53002},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1985__99_178211/}
}