  The mod-p cohomology ring of a non-trivial finite p-group is an infinite
dimensional, finitely presented graded unital algebra over the field with p
elements, with generators in positive degrees. We describe an effective
algorithm to test if two such algebras are graded isomorphic. As application,
we determine all graded isomorphisms between the mod-p cohomology rings of all
p-groups of order at most 100.
