Observation of the decays B- to Ds(*)+ K- pi-
  We report first observations of the decays B- to Ds(*)+ K- pi-, using 292 fb^-1 of data collected at Upsilon(4S) resonance energy by the BaBar detector at the PEP II e+ e- collider. The branching fractions are measured to be B(B- to Ds+ K- pi-) = (1.88 +- 0.13 +- 0.41) x 10^-4 and B(B- to Ds*+ K- pi-) = (1.84 +- 0.19 +- 0.40) X 10^-4. 
The BABAR Collaboration, B. Aubert, et al