Ideal class groups of cyclotomic number fields I, by Franz Lemmermeyer
This paper has appeared in Acta Arith. 72 (1995), no.4, 347-359, and so
the dvi version has been removed.
We derive some results on Hasse's unit index of CM-fields,
and give algebraic proofs for some class number relations
due to Masley, Metsankyla, and Louboutin.
Franz Lemmermeyer <email@example.com>