In this paper we prove that a normal Gorenstein surface dominated by the
projective plane P^2 is isomorphic to a quotient P^2/G, where G is a finite
group of automorphisms of P^2 (except possibly for one surface V_8'). We can
completely classify all such quotients. Some natural conjectures when the
surface is not Gorenstein are also stated.Comment: Nagoya Mathematical Journal, to appea