2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/152115The quotients $Y=X/conj$ by the complex conjugation $conj\: X\to X$ for complex rational and Enriques surfaces $X$ defined over $\R$ are shown to be diffeomorphic to connected sums of $\barCP2$, whenever $Y$ are simply connected.7 pages, AMS-TeX, 2 hand-written figures available by requestDifferential Geometrytext