@article{MZ_1966__92_170552,
     author = {J\"urgen von von Steinen},
     title = {\"Uber {Ausdehnungen} von {Derivationen.}},
     journal = {Mathematische Zeitschrift},
     pages = {234--255},
     publisher = {mathdoc},
     volume = {92},
     year = {1966},
     zbl = {0158.28502},
     url = {http://geodesic.mathdoc.fr/item/MZ_1966__92_170552/}
}