@article{MZ_1963__81_170148,
     author = {Josef Schmid},
     title = {\"Uber eine {Klasse} von {Verkettungen.}},
     journal = {Mathematische Zeitschrift},
     pages = {187--205},
     publisher = {mathdoc},
     volume = {81},
     year = {1963},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MZ_1963__81_170148/}
}