Topological Methods in Nonlinear Analysis publishes research and survey papers on a wide range of nonlinear analysis, giving preference to those which employ topological methods.
Nirenberg-Gagliardo interpolation inequality and regularity of solutions of nonlinear higher order equations
F. Nicolosi, et al. (1996)
Regularity for viscosity solutions of fully nonlinear equations $F(D^2u) = 0$
Xavier Cabré, et al. (1995)