Observed gamma-ray luminosity of galactic SNRs in the TeV band; blue markers indicate upper limits. The red curves reflect the models with Bohm-like diffusion and indicate inverse-Compton (solid lines) and pion-decay (dashed lines) emission. The thick curves are calculated for a ambient gas density of 0.4 cm⁻³. The shaded uncertainty bands represent the range of luminosity expected for a density in the range 0.04 − 4.0 cm⁻³. The references for the data points are given in the text.