@article{MOMA_1973__77_177641,
     author = {W. Ziller},
     title = {Torsion von {Minimalfl\"achen.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {172--179},
     year = {1973},
     volume = {77},
     zbl = {0256.53005},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1973__77_177641/}
}