Many papers written jointly by Olga and Nina Ural'tseva were devoted to the investigation of quasilinear elliptic and parabolic equations of the second order.
Maraming mga papeles na nakasulat sa pamamagitan ng sama-sama Olga at Nina Ural'tseva ay mapagmahal sa imbestigasyon ng quasilinear tambilugin at paparabola equation ng pangalawang order.