References
- Fried , M. D. and Jarden , M. 1986 . Field Arithmetic , A Series of Modern Surveys in Mathematics Berlin : Springer .
- Halmos , P. R. 1974 . Naive Set Theory , Undergraduate Texts in Math New York : Springer-Verlag .
- Iwasawa , K. 1953 . On solvable extensions of algebraic number fields . Ann. Math. , 58 : 548 โ 572 .
- Ribes , L. and Zalesskii , P. 2000 . Profinite Groups , A Series of Modern Surveys in Mathematics Berlin : Springer .
- #Communicated by E. Zelmanov.