2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68148We study the geography and birational geometry of 3-fold conic bundles over P^2 and cubic del Pezzo fibrations over P^1. We discuss many explicit examples and raise several open questions. This paper was submitted to the proceedings of the "Fano conference" held in Torino in October 2002.40 pages, submitted to the proceedings of the "Fano conference" held in Torino in October 2002Algebraic Geometry14E30; 14E05text