Dust Features of Visually Bright AGB Variables as Seen by ISO and IRAS

ISO-SWS spectra of two Mira variables (R Cas and T Dra), taken at two different pulsational phases, are presented. We describe the reduction of the data and the encountered problems. The dust features observed by ISO at different phases and with the Low Resolution Spectrometer of IRAS are compared. We briefly discuss the results in terms of current models for the circumstellar dust shells of AGB variables. This revised version was published online in September 2006 with corrections to the Cover Date.