“…Moreover, this method was further effectively applied to studying solutions to a generalized [5] where N ∈ Z + , u ∈ M 1 ⊂ C ∞ (R/2πZ; R) is a smooth function on a periodic functional manifold M 1 and t ∈ R is the evolution parameter. Making use of novel methods, devised in [8,18,25] and based both on the spectral theory [10,17,19,20] and differential algebra techniques, the Lax type representations for the cases N = 1, 4 were constructed in explicit form.…”