Abundance results for the α-elements. Literature data for the MW (black dots) are as follows: for the halo, Roederer et al. (2014); for the bulge, Johnson et al. (2012, 2014); and for the disks, Bensby et al. (2014). Pal 13 is shown as the orchid star, where the error bar accounts for both statistical and systematic uncertainties. Blue filled points indicate the abundances of the comparison GCs (see Table 5 for references), while open blue symbols denote outer halo GCs beyond 20 kpc that have not been uniquely assigned to a specific progenitor. We also show as red circles the results from our systematic coadded abundance study of outer halo GCs (Koch et al. 2009; Koch & Côté 2010, 2017).