  We consider three different approaches (by Ashtekar, Bonga and Kesavan; Hoque
and Virmani; and Dobkowski-Ry\l{}ko and Lewandowski) to investigate
gravitational radiation produced by time changing matter source in de Sitter
spacetime. All of them lead to generalizations of the quadrupole formula,
however, due to different gauge conditions and choices of the hypersurfaces,
across which the energy flux is computed, it is nontrivial to see that they all
coincide, as one would expect from the symplectic theory. Each of the
expressions for the radiated energy in the form of gravitational waves is
expressed in terms of the mass and pressure quadrupole moments and written
explicitly up to the linear order in $\sqrt{\Lambda}$, or equvalently in Hubble
parameter $H$. It is shown that up to the first order all three of the
generalizations of the quadrupole formula agree.
