2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41017High precision analyses of experimental data for e+ e- annihillation, such as determination of jet rates or event shape observables, call for complete next-to-next-to-leading order (NNLO) perturbative QCD predictions. In this talk, we discuss the various ingredients entering the calculation of the NNLO corrections in e+ e- annihillation.6 pages, talk given at the Europhysics Conference on HEP, Budapest, July 2001High Energy Physics - Phenomenologytext