[Ce/Y] values as function of metallicity for the stars analysed in de Castro et al. (2016) and Cseh et al. (2018) (grey dots), with the 28 stars analysed in this work indicated by the names and highlighted as black, blue, and red dots, with colour depending on Groups 1, 2, and 3 presented in Sect. 4, respectively. For sake of clarity, the error bars are marked only for the stars analysed in this paper, and the three Ba stars at [Fe/H] ≈ −1 are not shown.