Heavy-element abundances in the programme stars normalised to their La abundance (Z = 57). The blue boxes refer to the four N-rich stars, whereas black boxes depict the range covered by all the other stars. The bottom and top of the boxes refer to the 25th and 75th percentiles in the considered elemental abundance. The light and heavy s-elements (ls and hs) are delineated by the atomic number Z = 57.