SED fits for the sample stars (solid line) to the ISO spectra (black dots) and photometric points from IRAS (filled green circles). The PACS (blue dots) and SPIRE (cyan dots) spectra are also plotted when available. The published photometric data (open circles) are taken from Dyck et al. (1974) and Epchtein et al. (1980) for WX Psc, Persi et al. (1990) for OH 127.8+0.0, Garcia-Lario et al. (1997) and Lepine et al. (1995) for AFGL 5379, Werner et al. (1980) for OH 26.5+0.6, and Justtanont et al. (2006) for both OH 26.5+0.6 and OH 30.1-0.7.