  Recently, it was proposed to use measurements of Bd(t) -> D(*)+ D(*)- and Bd
-> Ds(*)+ D(*)- decays to measure the CP phase gamma. In this paper, we present
the extraction of gamma using this method. We find that gamma is favored to lie
in one of the ranges [19.4o - 80.6o] (+ 0o or 180o), [120o - 147o] (+ 0o or
180o), or [160o - 174o] (+ 0o or 180o) at 68% confidence level (the (+ 0o or
180o) represents an additional ambiguity for each range). These constraints
come principally from the vector-vector final states; the vector-pseudoscalar
decays improve the results only slightly. Although, with present data, the
constraints disappear for larger confidence levels, this study does demonstrate
the feasibility of the method. Strong constraints on gamma can be obtained with
more data.
