A(F) vs. A(C) for different objects in the Galaxy. Symbols stand for: s-rich M 22 stars (filled circles), s-poor M 22 stars (open circles), NGC 6712 (crosses: Yong et al. 2008), M 4 (open squares: Smith et al. 2005), bulge stars (filled squares: Cunha et al. 2008), Ba star (filled triangle: Alves-Brito et al. 2011), Orion giant stars (open triangles: Cunha & Smith 2005; Cunha et al. 2008), CEMP and AGB stars (stars: Schuler et al. 2007; Abia et al. 2009). The hachured area indicates the A(F)-A(C) position of Galactic AGB stars analyzed in Abia et al. (2010).