Eu and Fe abundance trends with ranks. Left panel: Eu abundances versus their corresponding ranks. The integer rank passes, with increasing Eu abundances, through all observational points from the smallest to the highest abundance. The trend deviates strongly from a linear behavior at high Eu ranks, indicating a second highly productive Eu source. Right panel: Fe abundances versus their corresponding ranks (including all stars with Fe detection, independent of the fact whether they also contain Eu or not). The figure shows a close to linear relation with deviations at low and high Fe ranks.