Energy-momentum of gravitational waves in general relativity theory

It is shown that if to follow closely the method of calculating the ''flux of energy''of gravitational waves, suggested by Einstein and use only the generally covariant Lagrangian density, then one gets the value of the ''flux of energy'' of gravitational waves equal to zero. Thus the way which has been chosen by Einstein and which leads to introducing the noncovariant ''pseudotensors'' into the covariant physical theory, leads also to the zero value of the ''energy'' in general relativity theory. The treatment leads to the conclusion that despite the inclination it is impossible to attribute one and the same sense to the notion of energy-momentum both in general relativity theory and in all other physical theories