Nonlinear perturbed integral equations related to nonlocal boundary   value problems
  By topological arguments, we prove new results on the existence, non-existence, localization and multiplicity of nontrivial solutions of a class of perturbed nonlinear integral equations. These type of integral equations arise, for example, when dealing with boundary value problems where nonlocal terms occur in the differential equation and/or in the boundary conditions. Some examples are given to illustrate the theoretical results. 
Alberto Cabada, Gennaro Infante, F. Adri\'an F. Tojo
math.CA