title: Null-field radiationless sources: comment.
abstract: We elaborate on a recent paper by Hurwitz and Gbur [Opt. Lett.39, 6529 (2014)], dealing with null-field sources. After commenting on their theory in Minkowski space, we show how the theory can be conveniently generalized to the case of curvilinear space.
authors.forename: Iver
authors.initials: I
authors.lastname: Brevik