The Li-cycle diagram according to de La Reza et al. (1997). Filled and open symbols represent different IRAS catalogs: PSC − Point Source Catalog, FSC − Faint Source Catalog, respectively. Color coding is the same as in Fig. 7. Symbols stand for IRAS fluxes quality: circles − both colors have good quality, triangles pointing left − upper limit for [25−12], triangles pointing down − upper limit for [60−25], diamonds − upper limits for both colors.