“…Hence, over the last years, it has been realized that the global relation can be solved numerically, using various techniques. The first class of those methods involves the pointwise collocation of the global relation on the spectral plane, [33,53,55,59,82,86,87,88,90], while recently, a Galerkin approach for the global relation has been introduced, [8,9,10]. In this Chapter, the main focus lies on the approach using collocation-type techniques.…”