D. Giachetti et al., ON THE REGULARITY OF VERY WEAK MINIMA, Proceedings of the Royal Society of Edinburgh. Section A. Mathematics, 126, 1996, pp. 287-296
We consider very weak minimisers u of variational integrals integral F
(x, Du(x)) dx and very weak solutions u of nonlinear elliptic systems
div A(x, u, Du) = 0; we prove higher integrability for the gradient Du
without any homogeneity on xi --> A(x, u, xi), thus improving on a re
sult by Iwaniec and Sbordone.