Solar and Solar-type Stars Atmosphere's Activity at 11-year and   Quasi-biennial Time Scales
  We studied new simultaneous observations of the flux variations of the photospheric and chromospheric emissions of 33 solar-type stars and Sun during the HK-project that were conducted over the past 20 years. In addition to the known cyclic chromospheric emission variations of stars at the 11-year time scale, which were discovered at the Mount Wilson Observatory, we found a recurrences that are similar to the quasi-biennial variations of solar radiation. The results of calculations of the radiation fluxes variations periods of stars at the quasi-biennial scale are given. 
E.A.Bruevich, E.V. Kononovich
astro-ph.SR