On integrable structures for a generalized Monge-Ampere equation
  We consider a 3rd-order generalized Monge-Ampere equation u_yyy - u_xxy^2 + u_xxx u_xyy = 0 (which is closely related to the associativity equation in the 2-d topological field theory) and describe all integrable structures related to it (i.e., Hamiltonian, symplectic, and recursion operators). Infinite hierarchies of symmetries and conservation laws are constructed as well. 
Paul Kersten, Iosif Krasil'shchik, Alexander Verbovetsky, and Raffaele   Vitolo
nlin.SI math-ph math.MP