State Observers for Linear Systems with Uncertainty Sergey K. Korovin, Vasily V. Fomichev E-Book (pdf)

Homotopy of Extremal Problems Stanislav V. Emelyanov, Sergey K. Korovin, Nikolai A. Bobylev E-Book (pdf)

Approximation Procedures in Nonlinear Oscillation Theory Nikolai A. Bobylev, Yurii M. Burman, Sergey K. Korovin E-Book (pdf)