“C1,α Regularity of Viscosity Solutions of Fully Nonlinear Elliptic PDE Under Natural Structure Conditions”, J. Part. Diff. Eq., vol. 6, no. 3, pp. 193–216, Jun. 1993, Accessed: Feb. 27, 2026. [Online]. Available: https://global-sci.com/index.php/jpde/article/view/3745