Diana S. Maltseva, Roman O. Popovych, “Point-symmetry pseudogroup, Lie reductions and exact solutions of Boiti–Leon–Pempinelli system”, Physica D: Nonlinear Phenomena, 460 (2024), 134081
Pogrebkov A.K., “Kadomtsev-Petviashvili Hierarchy: Negative Times”, Mathematics, 9:16 (2021), 1988
А. К. Погребков, “Коммутаторные тождества на ассоциативных алгебрах и интегрируемость нелинейных эволюционных уравнений”, ТМФ, 154:3 (2008), 477–491 ; A. K. Pogrebkov, “Commutator identities on associative algebras and the integrability of nonlinear evolution equations”, Theoret. and Math. Phys., 154:3 (2008), 405–417