V. I. Arnol

Remarks on the perturbation theory for problems of Mathieu type

V. I. Arnol, 2005 .

THE STURM THEOREMS AND SYMPLECTIC GEOMETRY

V. I. Arnol, 2004 .

The Lévy transformations of semi-Hamiltonian systems

V. Sokolov, E. Ferapontov, V. I. Arnol, 2017 .

Non-standard analysis and singular perturbations of ordinary differential equations

A. Borovkov, I. Shafarevich, M. Freidlin, 2016 .