  The purpose of the classical Einstein and Landau-Lifshitz pseudotensors is
for determining the gravitational energy. Neither of them can guarantee a
positive energy in holonomic frames. In the small sphere approximation, it has
been required that the quasilocal expression for the gravitational
energy-momentum density should be proportional to the Bel-Robinson tensor
$B_{\alpha\beta\mu\nu}$. However, we propose a new tensor
$V_{\alpha\beta\mu\nu}$ which is the sum of certain tensors
$S_{\alpha\beta\mu\nu}$ and $K_{\alpha\beta\mu\nu}$, it has certain properties
so that it gives the same gravitational "energy-momentum" content as
$B_{\alpha\beta\mu\nu}$ does. Moreover, we show that a modified Einstein
pseudotensor turns out to be one of the Chen-Nester quasilocal expressions,
while the modified Landau-Lifshitz pseudotensor becomes the Papapetrou
pseudotensor; these two modified pseudotensors have positive gravitational
energy in a small region.
