1. V. I. Arnold, V. V. Kozlov and A. I. Neishtadt, Mathematical Aspects of Classical and Celestial Mechanics (Springer, 1997).
2. C. S. Gardner, J. M. Green, M. D. Kruskal and R. M. Miura, “Method for solving the Korteweg-de Vries equation,” Phys. Rev. Lett. 19, 1095 (1967).
3. V. E. Zakharov and L. D. Faddeev, “Korteweg-de Vries equation: a completely integrable Hamiltonian system,” Funct. Anal. Appl. 5 (4), 280–287 (1971).
4. V. E. Zakharov, A. Takhtadzhyan and L. D. Faddeev, “Complete description of solutions of the’ sine-Gordon’ equation,” Soviet Phys. Dokl. 19 (12), 824–826 (1974).
5. I. Ya. Arefeva and V. Korepin, “Scattering in two-dimensional model with Lagrangian (1/γ)((∂μu)2/2 + m2(cos u–1)),” Pisma JETP Lett. 20 (10), 680–684 (1974).