Volvach, A. E.Riabov, Mykhailo I.Volvach, L. N.Sukharev, Artem L.Aller, H. D.Aller, M. F.2010-08-192010-08-192009"Astrophysics and cosmology after Gamow: recent progress and new horizons" (2009, Odessa) Gamow memorial international conference dedicated to 105-th anniversary of George Gamow Program and abstracts..., August 17-23, 2009 / chairman: V.A. Smyntyna. - Odessa: Astroprint, 2009. - 40p.https://dspace.onu.edu.ua/handle/123456789/76"Astrophysics and cosmology after Gamow: recent progress and new horizons" (2009, Odessa) Gamow memorial international conference dedicated to 105-th anniversary of George Gamow Program and abstracts..., August 17-23, 2009 / chairman: V.A. Smyntyna. - Odessa: Astroprint, 2009. - 40p.ccVariations in the radio flux of 3C120, 3C273, 3C279, 3C345, 3C 454.3 are analyzed using long-term monitoring data at five frequencies from 4.8 to 36.8 GHz obtained at the University ofMichigan Radio Astronomy Observatory and the Crimean Astrophysical Observatory. A spectral analysis of the light curves at the various frequencies reveals the presence of periodic components. Using method of model calculations for each of the found period tested its ability to reproduce the observed flux variability at different frequencies. On the basis of the model calculations presented the catalog of the most reliable periods of flux variable of radio sources.enactive galactic nucleiradio sourcesblazarsArticle