  In this paper we consider Lipschitz graphs of functions which are stationary
points of strictly polyconvex energies. Such graphs can be thought as integral
currents, resp. varifolds, which are stationary for some elliptic integrands.
The regularity theory for the latter is a widely open problem, in particular no
counterpart of the classical Allard's theorem is known. We address the issue
from the point of view of differential inclusions and we show that the relevant
ones do not contain the class of laminates which are used in [22] and [25] to
construct nonregular solutions. Our result is thus an indication that an
Allard's type result might be valid for general elliptic integrands. We
conclude the paper by listing a series of open questions concerning the
regularity of stationary points for elliptic integrands.
