Smooth Solutions to a Class of Nonlocal Fully Nonlinear Elliptic Equations Hui Yu Indiana University Mathematics Journal 2017 text pdf 10.1512/iumj.2017.66.6218 10.1512/iumj.2017.66.6218 en Indiana Univ. Math. J. 66 (2017) 1895 - 1919 state-of-the-art mathematics http://iumj.org/access/