... There are preliminary series of photometric and radio spectral observations of the above-mentioned stars, archival data on the light curves of the stars, results of the search for OH and H 2 O maser emission in IRAS point sources that possess the IR parameters similar to Miras. ... The aim is a detailed study of the maser emission variability. ... In 1996-1997, astronomical observations of Mira Ceti-type stars (miras) were carried out in three spectral ranges: optical, infrared, and radio. ...