[O/Fe] vs. [Fe/H] for present results compared with published abundances for halo and bulge stars. Panel a): plotted in the metallicity range −1.5 < [Fe/H] < + 0.7, corresponding to that of sample bulge giant stars, compared with the bulge dwarfs by Bensby et al. (2013), giant stars from Alves-Brito et al. (2010) which is a revision of Meléndez et al. (2008), Cunha & Smith (2006), Johnson et al. (2014), Rich & Origlia (2005) and Fulbright et al. (2006, 2007); panel b): bulge giants from the present work, and thick disk stars by Alves-Brito et al. (2010), Bensby et al. (2004) and Reddy et al. (2006).