Elemental abundance ratios of stars in Group 3 (filled circles) and comparison stars (open circles). The star BD +35 3659, which was removed from Group 3, is marked by an asterisk. For this comparison the data for Milky Way thin-disc dwarfs are plotted: Mishenina et al. (2013, dots), Mashonkina et al. (2007, crosses), Reddy et al. (2006, 2003, squares), Brewer & Carney (2006, diamonds), Bensby et al. (2005, stars), Koch & Edvardsson (2002, upside down triangles), Gratton & Sneden (1994, triangles), Edvardsson et al. (1993, plus signs). Solid lines show the Galactic thin-disc chemical evolution models by Pagel & Tautvaišienė (1997). Average uncertainties are shown in the box for zirconium.