Let X be a connected compact
Hausdorff space, and G a finite abelian group. In this note we obtain a short exact
sequence (Theorem 1) which describes the group of isomorphism classes of regular
covering spaces of X with group G. The sequence is derived as an immediate
translation of a similar sequence involving the group of commutative Galois
extensions with group G of C(X), the ring of complex-valued continuous functions on
X.