TOPOLOGY AND ITS APPLICATIONS, vol.79, no.2, pp.121-128, 1997 (SCI-Expanded)
The quotients Y = X/conj by the complex conjugation conj:X --> X for complex rational and Enriques surfaces X defined over R are shown to be diffeomorphic to connected sums of <(CP)over bar>(2), whenever the Y are simply connected. (C) 1997 Elsevier Science B.V.