Branched coverings of $C{P}^2$ and other basic 4-manifolds

We give necessary and sufficient conditions for a 4-manifold to be a branched covering of $C{P}^2$, $S^2\times S^2$, $S^2{S}^2$ and $S^3 \times S^1$, which are expressed in terms of the Betti numbers and the intersection form of the 4-manifold.