Petrishin R I

Publications in Math-Net.Ru

1. On integral manifolds of multifrequency oscillatory systems
   
   Izv. Akad. Nauk SSSR Ser. Mat., 54:2 (1990),  378–395
2. The averaging method in some boundary value problems
   
   Differ. Uravn., 25:6 (1989),  956–964