ON THE CONNECTION BETWEEN FIRST INTEGRALS, INTEGRAL INVARIANTS AND POTENTIALITY OF EVOLUTIONARY EQUATIONS СтатьяSavchin V.M., Budochkina S.A., Gondo Y., Slavko A.V.Eurasian Mathematical Journal. Том 9. 2018. С. 82-90
CONSTRUCTION OF VARIATIONAL FACTORS FOR QUASILINEAR SECOND ORDER PARTIAL DIFFERENTIAL EQUATIONS СтатьяFilippov V.M., Mikailovna S.P., Gondo Y.Computer Physics Communications. Том 126. 2000. С. 67-71