A Canonical Frame for Nonholonomic Rank Two Distributions of Maximal   Class
  In 1910 E. Cartan constructed the canonical frame and found the most symmetric case for maximally nonholonomic rank 2 distributions on a 5-dimensional manifold. We solve the analogous problems for rank 2 distributions on an n-dimensional manifold for arbitrary n greater than 5. Our method is a kind of symplectification of the problem and it is completely different from the Cartan method of equivalence. 
Boris Doubrov and Igor Zelenko