Contact equivalence problem for KDV-type equations
  The Cartan's method of equivalence and moving coframe method has been applied to solve the local equivalence problem for KDV-type equations under the action of a pseudo-group of contact transformations. The structure equations, the sets of differential invariants for symmetry groups and equivalent conditions of these equations are found. 
Mostafa Hesamiarshad, Mehdi Nadjafikhah
math.DG