Experimental Status of Semileptonic B Decays - Recent Results from LEP   and Comparisons with Y(4S) Experiments
  Recent analyses of the LEP and Y(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. 
Marco Battaglia