First observations of (B)over-bars0 → D+D-, Ds+D- and D0(D)over-bar0 decays - Aaij, R; Abellan, Beteta C; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; et al. (PHYSICAL REVIEW D, 2013)