2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/40400Recent analyses of the LEP and Upsilon(4S) data have better outlined the picture of semileptonic B decays. Results on inclusive and exclusive decay branching fractions and on the extraction of the |Vub| and |Vcb| elements of the CKM mixing matrix are discussed, together with some of the still open questions and the sources of model systematics.15 pages, 6 figures, to apper in the Proceedings of the 5th Workshop on Heavy Quarks at Fixed Target, Rio de Janeiro, October 2000High Energy Physics - Phenomenologytext