For the discussion of ${\it V}_{\it ub}$ measurements, which is not repeated here, see the review on "Determination of $\vert {\it V}_{\it cb}\vert $ and $\vert {\it V}_{\it ub}\vert $."

The CKM matrix element $\vert {\it V}_{\it ub}\vert $ can be determined by studying the rate of the charmless semileptonic decay ${{\mathit b}}$ $\rightarrow$ ${{\mathit u}}{{\mathit \ell}}{{\mathit \nu}}$. The relevant branching ratio measurements based on exclusive and inclusive decays can be found in the ${{\mathit B}}$ Listings, and are not repeated here.

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