Concurrency of anisotropy and spatial dispersion in low refractive index   dielectric composites
  The article demonstrates uncommon manifestation of spatial dispersion in low refractive index contrast 3D periodic dielectric composites with periods of about one tenth of the wavelength. First principles simulations by the well established plane wave method reveal that spatial dispersion leads to appearance of additional optical axes and can compensate anisotropy in certain directions. 
Andrey A. Ushkov and Alexey A. Shcherbakov
physics.optics