“…Analogous results have been obtained in [10] and [11] under the assumption that the matrix A satisfies the Dini mean oscillation condition, which is weaker than the classical Dini condition. Note also the paper [23], where some additional regularity of solutions along level sets has been established. In the papers [1], [2] some interesting counter-examples were constructed and the so-called renormalized solutions were studied, in particular, an example was constructed of a positive definite and continuous diffusion matrix A for which the equation ∂ x i ∂ x j (a ij ̺) = 0 has a locally unbounded solution.…”