Examples of spectral synthesis of metal-poor stars with [Fe/H] <−1.5. Colour dots and solid lines indicate observed and synthesized spectra, respectively. Vertical dash lines are the locations of Pd and Ag lines analyzed in this work. The Ag i λ 3382.9 Å region of G 88-10 and the Ag i λ 3382.9 Å regions of G 20-24 and BD +21 607 are severely affected by noise or do not show any absorption feature. The pixels in the Ag i λ 3382.9 Å region of G 13-9 and Ag i λ 3280.7 Å region of G 20-24 and BD +17 4708 were affected by cosmic rays, preventing us from any spectral synthesis. Ag abundance detections were obtained only for BD +17 4708 and BD +21 607 with Ag i λ 3280.7 Å and only for G 88-10 and G 10-4 with Ag i λ 3382.9 Å in this figure. Pd abundance detection were obtained for four stars with Pd i λ 3404.6 Å (see Table 2).