  We consider the Nernst-Ettingshausen (NE) effect in the presence of
semiclassically strong magnetic fields for a quasi-two dimensional system with
a parabolic or linear dispersion of carriers. We show that the occurring giant
oscillations of the NE coefficient are coherent with the recent experimental
observation in graphene, graphite and bismuth. In the 2D case we find the exact
shape of these oscillations and show that their magnitude decreases/increases
with enhancement of the Fermi energy for Dirac fermions/normal carriers. With a
crossover to 3D spectrum the phase of oscillations shifts, their amplitude
decreases and the peaks become asymmetric.
