@article{MZ_1970__114_171310,
     author = {Helmut Lenzing},
     title = {\"Uber koh\"arente {Ringe.}},
     journal = {Mathematische Zeitschrift},
     pages = {201--212},
     publisher = {mathdoc},
     volume = {114},
     year = {1970},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MZ_1970__114_171310/}
}