...VV: Lie algebras and equations of Korteweg-de Vries type, J. Soviet Math. 30 (1985), 1975-2036. 5. Libermann, P. and Marie, CM: Symplectic Geometry and Analytical Mechanics, Reidel, Dordrecht, 1987. 6. Magnano, G. and Magri, F: Poisson-Nijenhuis structures and Sato hierarchy, Rev. Math. Phys. 3(4)...