1. An exact theory of nonlinear waves on a Lagrangian-mean flow;Andrews;J. Fluid Mech.,1978
2. On wave-action and its relatives;Andrews;J. Fluid Mech.,1978
3. Bjerknes, V., , J., Bjerknes, , H., Soldberg, , T., Bergeron, , Physikalische Hydrodynamik, 1-8 Springer-Verlag, New York, 1933,
4. Magnetic field line Hamiltonian;Boozer,1985
5. Boussinesq, J., , Théorie Analytique de la Chaleur, , 2, Gauthier-Villars, Paris, 1903,