I Bakas, A C Kakas, “Extended conformal symmetries and U(1) currents”, J. Phys. A: Math. Gen., 22:9 (1989), 1451
J Gibbons, B A Kupershmidt, “Kinetic representation of discrete integrable systems”, J. Phys. A: Math. Gen., 22:13 (1989), L559
I. Bakas, “Hamiltonian reduction and conformal symmetries in two dimensions”, Physics Letters B, 219:2-3 (1989), 283
I. M. Ivochkina, “Description of the algebraic structure of second-order differential operators that can be represented in divergence form”, J Math Sci, 45:3 (1989), 1117
Yoshihide Watanabe, “A Hamilton formalism for evolution equations with odd variables”, Annali di Matematica pura ed applicata, 154:1 (1989), 127
John Gibbons, Boris A. Kupershmidt, “Kinetic representation of the KP hierarchy”, Physics Letters A, 139:3-4 (1989), 141
В. В. Соколов, “О симметриях эволюционных уравнений”, УМН, 43:5(263) (1988), 133–163 ; V. V. Sokolov, “On the symmetries of evolution equations”, Russian Math. Surveys, 43:5 (1988), 165–204
Pierre Mathieu, “Extended classical conformal algebras and the second hamiltonian structure of Lax equations”, Physics Letters B, 208:1 (1988), 101
Peter J. Olver, Yavuz Nutku, “Hamiltonian structures for systems of hyperbolic conservation laws”, Journal of Mathematical Physics, 29:7 (1988), 1610
Pierre Mathieu, “Supersymmetric extension of the Korteweg–de Vries equation”, Journal of Mathematical Physics, 29:11 (1988), 2499