The gravitational energy-momentum pseudo-tensor of conformally invariant theories of gravity

We construct the gravitational energy-momentum pseudo-tensor of up to fourth-order conformally invariant theories of gravity. Then we linearize the pseudo-tensor and use its average over a macroscopic region to find the energy and momentum carried by the plane gravitational waves of the three main conformally invariant theories of gravity.
Comment: 17 page, no figures; v2: references added