# Anisotropic elliptic problems

• Where can I find a reference on the following anisotropic problem? (\bullet) \qquad \begin{align*} \nabla_x (A(x) \nabla_x u(x,y)) + \Delta_y(K(y) \ast u(x,y))\end{align*}=0, where $$(x,y) \in \mathbb{R}^{N_1}\times \mathbb{R}^{N_2}$$, and $$K$$ is some (not necessarily smooth) "convolution kernel" and $$A$$ is uniformly elliptic.

• What are other references problems with anisotropies similar or related to $$(\bullet)$$? That is problems with different (possibly nonlocal) ellipticity coefficients for the space variables $$(x,y) \in \mathbb{R}^{N_1}\times \mathbb{R}^{N_2}$$.