1. The existence of a denumerable set of periodic motions in four-dimensional space in an extended neighborhood of a saddle-focus;Sil'nikov;Soviet Math. Dokl.,1967
2. The existence of a countable set of periodic motions in the neighborhood of a homoclinic curve;Sil'nikov;Soviet Math. Dokl.,1967
3. On a Poincaré-Birkhoff problem;Sil'nikov;Math. USSR-Sb.,1967