Universal Isgur-Wise form factors from QCD sum rules in HQET
  We review the role of the universal Isgur-Wise functions parameterizing the $B$ meson semileptonic matrix elements to charm states in the infinite heavy quark mass limit. We also discuss the determination of one of such form factors by QCD sum rules in the framework of the Heavy Quark Effective Theory. 
P. Colangelo, F. De Fazio, N. Paver