[Mg,Si,Ca/Fe] versus [Fe/H] for bulge spheroid stars. Filled blue pentagons show the ASPCAP results for the present sample; filled yellow pentagons the ASPCAP results for the sample described in Razera et al. (2022). For the chemical-evolution models, different model lines correspond to the outputs of models computed for radii of r < 0.5, 0.5 < r < 1, 1 < r < 2, and 2 < r < 3 kpc from the Galactic centre. Black lines correspond to specific star formation of ν =1 Gyr⁻¹, and blue lines refer to ν =3 Gyr⁻¹.