1. G. Cornell and M. Rosen, The class group of an Abelian l-extension, Illinois J. Math., to appear.
2. On class field towers and the rank of ideal class groups;Furuta;Nagoya Math. J.,1972
3. Extensions of the Hasse norm theorem;Garbanati;Bull. Amer. Math. Soc.,1975
4. Hilbert class fields and split extension;Gold;Illinois J. Math.,1977
5. The principal genus and Hasse's norm theorem;Gold;Indian J. Math.,1977