A characterization of efficient points in constrained location problems with regional demand

In this paper we characterize the set of efficient points in the planar point-objective location problem under a convex locational constraint, when distances are measured by a strictly convex norm in ~2 and the set of demand points is a compact set. It is shown that, under these assumptions, the efficient set coincides with the closest-point projection of the convex hull of the demand points onto the feasible set