1. A. Brumer, On the Picard group of 𝑄^{𝑎𝑏} (to appear).
2. G. Cornell, Relative genus theory and the class group of 𝑙-extensions (in preparation).
3. \bysame, A note on the 𝑍̂-extension of 𝑄 (in preparation).
4. G. Frey, MR 50 #2126.
5. The genus field and genus group in finite number fields. I, II;Frölich, A.;Mathematika,1959