Remarks on multisymplectic reduction

The problem of reduction of multisymplectic manifolds by the action of Lie groups is stated and discussed, as a previous step to give a fully covariant scheme of reduction for classical field theories with symmetries.
Comment: 9 pages. The definition of bracket of Hamiltonian forms has been corrected (and an acknowledgment to Prof. C. Blacker has been added in the "Acknowledgments")