@incollection{AST_1975__24-25__57_0,
     author = {Koch, Helmut and Venkov, B. B.},
     title = {\"Uber den $p$-klassenk\"orperturm eines imagin\"ar-quadratischen zahlk\"orpers},
     booktitle = {Journ\'ees arithm\'etiques de Bordeaux},
     series = {Ast\'erisque},
     pages = {57--67},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {24-25},
     year = {1975},
     mrnumber = {392928},
     zbl = {0335.12021},
     language = {de},
     url = {http://www.numdam.org/item/AST_1975__24-25__57_0/}
}