  We present a combined measurement of the production cross section of VZ (V=W
or Z) events in final states containing charged leptons (electrons or muons) or
neutrinos, and heavy flavor jets, using data collected by the CDF and D0
detectors at the Fermilab Tevatron Collider. The analyzed samples of ppbar
collisions at sqrt(s)=1.96 TeV correspond to integrated luminosities of 7.5 -
9.5 fb-1. Assuming the ratio of the production cross sections sigma(WZ) and
sigma(ZZ) as predicted by the standard model, we measure the sum of the WZ and
ZZ cross sections to be 4.47 +- 0.64 (stat) +0.73 -0.72 (syst) pb. This is
consistent with the standard model prediction and corresponds to a significance
of 4.6 standard deviations above the background-only hypothesis.
