Recently P.G. Grinevich and P.M. Santini suggested simple approximate formulas for solving periodic Cauchy problem for the focusing Nonlnear Schrodinger Equation (NLS) under assumption that one starts from a small perturbation of the unstable condensate and the number of unstable modes is not too large. With the help of these results, optical experiments in photorefractive crystal where conducted, in which the second and third return of anomalous waves was observed. A good agreement between the experimental data and the predictions made on the basis of the NLS theory was obtained. P.G. Grinevich was supported by the Russian Science Foundation grant No. 18-11-00316.