  We construct an explicit de Rham isomorphism relating the cohomology rings of
Banagl's de Rham and spatial approach to intersection space cohomology for
stratified pseudomanifolds with isolated singularities. Intersection space
(co-)homology is a modified (co-)homology theory extending Poincar\'e Duality
to stratified pseudomanifolds. The novelty of our result compared to the de
Rham isomorphism given previously by Banagl is, that we indeed have an
isomorphism of rings and not just of graded vector spaces. We also provide a
proof of the de Rham Theorem for cohomology rings of pairs of smooth manifolds
which we use in the proof of our main result.
