Scintillation times and decorrelation bandwidths for the pulsars B0329+54,
B1641-45, B1508+55 and B1919+21 are determined. The results are based on ob
servations made with different instruments and at different radio frequenci
es. All objects but the pulsar B1508+55 were detected to have more than one
frequency scale. The obtained values of scattering parameters are not cont
rary in general to the Kkolmogorov form of density fluctuation spectrum.