Algebraic Number Theory
《Algebraic Number Theory》 · 第 320 页 · Chapter V，Section 1「The Local Reciprocity Law」，Theorem 1.3
§ 1. The Local Reciprocity Law. […] (1.3) Theorem. For every finite Galois extension $L/K$ of local fields we have a canonical isomorphism $r_{L/K}:G(L/K)^{\mathrm{ab}}\xrightarrow{\sim}K^*/N_{L/K}L^*$.