  P. Baird and the second author studied harmonic morphisms from a
three-dimensional simply-connected space form to a surface and obtained a
complete local and global classification of them. In this paper, we obtain a
description of all harmonic morphisms from any three-dimensional Euclidean and
spherical space form to a surface, namely that any such harmonic morphism is
the composition of a standard harmonic morphism and a weakly conformal map. We
list the standard harmonic morphisms.

Differential Geometry;Differential Geometry