# Seeking reference on regularity theory for nonlinear elliptic PDE

Hello,

I am searching for a reference on a result I know must exist proving regularity for weak solutions of a (nonlinear, but well-behaved) elliptic homogeneous PDE. Working over say a bounded open subset of $\mathbb{R}^n$ would be fine, and I don't need to deal with very nonlinear PDE - quasilinear is enough for me. If someone can help locate a reference, I'd be very grateful!

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