  The analysis of individual pulses of four rotating radio transients (RRATs),
previously discovered in a monitoring survey running for 5.5 years at the
frequency of 111 MHz, is presented. At a time interval equivalent to five days
of continuous observations for each RRAT, 90, 389, 206, and 157 pulses were
detected in J0640+07, J1005+30, J1132+25, and J1336+33, respectively. The
investigated RRATs have a different distribution of the pulses amplitude. For
J0640+07 and J1132+25, the distribution is described by a single exponent over
the entire range of flux densities. For J1005+30 and J1336+33, it is a
lognormal function with a power law tail. For J0640+07 and J1005+30, we have
detected pulses with a signal-to-noise (S/N) ratio of few hundreds. For
J1132+25 and J1336+33, the S/N of the strongest pulses reaches several tens.
These RRATs show strong changing of character of emission. When strengths of
pulse amplitudes significantly changed, we see long intervals of absence of
emission or its strong attenuation. The analysis carried out in this work shows
that it is possible that all the studied RRATs are, apparently, pulsars with
giant pulses.
