2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/104730This paper surveys recent progress towards the Manin conjecture for (singular and non-singular) del Pezzo surfaces. To illustrate some of the techniques available, an upper bound of the expected order of magnitude is established for a singular del Pezzo surface of degree four.18 pagesNumber TheoryAlgebraic Geometry11G35 (14G05, 14G10)text