2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45830Processes with multiparticle final states in weakly coupled theories, both with and without instantons, cannot be studied perturbatively at most interesting energies and multiplicities. Semiclassical approaches to the calculation of their cross sections are reviewed.14 pages, LaTeX; to appear in Proceedings of 2nd Rencontres du Vietnam, October 1995High Energy Physics - Phenomenologytext