Filippenko V I

Publications in Math-Net.Ru

1. Some criteria for discreteness of the negative part of the spectrum of a linear differential operator
   
   Differ. Uravn., 21:4 (1985),  728–731
2. On the multiplicity of a spectrum of a first-order selfadjoint differential operator
   
   Differ. Uravn., 17:6 (1981),  1135–1138
3. On one class of non-selfadjoint differential operators with a discrete spectrum
   
   Differ. Uravn., 14:2 (1978),  383–384
4. Estimation of the multiplicity of the spectrum of a selfadjoint differential operator
   
   Differ. Uravn., 11:12 (1975),  2286–2287
5. Multiplicity of the spectrum of a self-adjoint ordinary differential operator of odd order
   
   Mat. Zametki, 17:4 (1975),  631–638