“…Two compact Riemannian manifolds will be said to be p-isospectral if their p-spectra coincide and in the literature, one abbreviates 0-isospectral to isospectral. It is well known that Spec p (M, g) does not determine the geometry of (M, g), as shown by many examples of nonisometric p-isospectral manifolds, via the so called generalized Sunada method (see for instance [Mi64], [Vi80], [Su85], [DG89]) working for all p and also with methods working for individual values of p (see for instance [Go86], [Ik88], [Gt00], [MR01], [GM06]). …”