Peter J. Olver, “Higher‐order symmetries of underdetermined systems of partial differential equations and Noether's Second Theorem”, Stud Appl Math, 147, no. 3, 2021, 904
Ian M. Anderson, Niky Kamran, “The variational bicomplex for hyperbolic second-order scalar partial differential equations in the plane”, Duke Math. J., 87, no. 2, 1997
Robert L. Bryant, Phillip A. Griffiths, “Characteristic cohomology of differential systems II: Conservation laws for a class of parabolic equations”, Duke Math. J., 78, no. 3, 1995
Victor Matveevich Buchstaber, Alexander Vasil'evich Mikhailov, “Интегрируемые полиномиальные гамильтоновы системы и симметрические степени плоских алгебраических кривых”, Успехи математических наук, 76, no. 4(460), 2021, 37
ENRIQUE G. REYES, GUILLERMO SANCHEZ, “EXPLICIT SOLUTIONS TO THE KAUP–KUPERSHMIDT EQUATION VIA NONLOCAL SYMMETRIES”, Int. J. Bifurcation Chaos, 17, no. 08, 2007, 2749
D K Demskoi, V V Sokolov, “On recursion operators for elliptic models”, Nonlinearity, 21, no. 6, 2008, 1253
Robert Conte, Micheline Musette, The Painlevé Handbook, 2020, 115
A. G. Meshkov, V. V. Sokolov, “Integrable Hamiltonian equations of fifth order with Hamiltonian operator D x”, Russ. J. Math. Phys., 22, no. 2, 2015, 201
Daryoush Talati, Abdul-Majid Wazwaz, “Some classification of non-commutative Integrable Systems”, Nonlinear Dyn, 88, no. 2, 2017, 1487
A.V. Kiselev, T. Wolf, “Classification of integrable super-systems using the SsTools environment”, Computer Physics Communications, 177, no. 3, 2007, 315