Solvability of boundary value problems for operator-differential equations of mixed type: the degenerate case. Pyatkov, S.G.; Abasheeva, N.L. — 2002 Sibirskij Matematicheskij Zhurnal
Solvability of boundary value problems for operator-differential equations of mixed type. Pyatkov, S.G.; Abasheeva, N.L. — 2000 Siberian Mathematical Journal
Some classes of inverse evolution problems for parabolic equations. Pyatkov, S.G.; Tsybikov, B.N. — 2009 Sibirskij Matematicheskij Zhurnal