2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/223311We discuss recent developments in multiloop calculations aiming eventually in computing the total cross section for e^+e^- annihilation into hadrons in order alpha_s^4.Comments: 5 pages, presented at the 7-th International Symposium on Radiative Corrections, Shonan Village (Japan), October 2005. The complete paper is also available via the www at http://www-ttp.physik.uni-karlsruhe.de/Preprints/High Energy Physics - Phenomenologytext