@article{MZ_1968__107_171076,
     author = {Reiner K\"uhnau},
     title = {Einige {Extremalprobleme} bei differentialgeometrischen und quasikonformen {Abbildungen.} {II}},
     journal = {Mathematische Zeitschrift},
     pages = {307--318},
     publisher = {mathdoc},
     volume = {107},
     year = {1968},
     zbl = {0172.10001},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__107_171076/}
}