  Nonlinearity arising from mutual interactions is one of the two main
difficulties to be addressed in inverse scattering. In this paper, we review
and describe under a common rationale some approaches which have been
introduced in literature in order to counteract nonlinearity. In particular, we
focus on possible rewritings of the Lippman Schwinger basic equation such to
reduce the degree of nonlinearity of inverse scattering problem. In detail,
three different rewritings are discussed and compared by emphasizing
similarities and the differences, and in the same rewriting spirit, we also
summarize and discuss the Virtual Experiments framework. Then, some possible
joint exploitations of the above concepts are introduced, discussed and tested
against numerical examples.
