Results of the FPF fits of f₁ to He I 667.82 nm, He I 587.56 nm, and Si III 455.26 nm spectral lines of NGC 6910-14. Top panels: line profiles, middle panels amplitudes, and bottom panels: phases. Observed profiles, amplitudes, and phases are plotted with black lines, their errors are marked with grey bars, and model fits are plotted with red lines. The profile of the He I 587.56 nm line near the core is disturbed by telluric lines.