1. Description of Degenerate Two-Dimensional Singularities with Single Critical Point

   • I. M. Nikonov

   OriginalPaper 11 July 2019 Pages: 87 - 97

2. Billiards and Integrability in Geometry and Physics. New Scope and New Potential

   • A. T. Fomenko
   • V. V. Vedyushkina

   OriginalPaper 11 July 2019 Pages: 98 - 107

3. Strengthened Ul’yanov’s Inequalities for Partial Moduli of Smoothness for Functions from Spaces with Various Metrics

   • M. K. Potapov
   • B. V. Simonov

   OriginalPaper 11 July 2019 Pages: 108 - 120

4. Reducibility of Linear Differential Systems to Linear Differential Equations

   • I. N. Sergeev

   OriginalPaper 11 July 2019 Pages: 121 - 126

5. On Some Analytic Method for Approximate Solution of Systems of Second Order Ordinary Differential Equations

   • O. B. Arushanyan
   • S. F. Zaletkin

   OriginalPaper 11 July 2019 Pages: 127 - 130

6. The Set of Lower Semi-Continuity Points of Topological Entropy of a Continuous One-Parametric Family of Dynamical Systems

   • A. N. Vetokhin

   OriginalPaper 11 July 2019 Pages: 131 - 133