Radio emission method is capable to study air shower physics independently from other shower components, including energy estimation of primary particle, longitudinal development of the particle cascade in the atmosphere (in the case of the Yakutsk array the depth of maximum development X$_{max}$), and thus, in the frame of chosen model, estimate mass composition of CR. Radio emission of air shower with energy E $ \sim 10^{20} $ eV was first registered and its characteristics obtained at the Yakutsk array. For the showers with energy E $\geq$ 10$ ^{19} $ eV arrival directions were tracked and reconstructed in galactic and equatorial coordinate system to search for search of CR sources with such energies.