1. The Furstenberg Boundary of Groupoids

   • Amini M.
   • Behrouzi F.

   OriginalPaper 23 September 2021 Pages: 773 - 781

2. On the Geometric Definition of Quasiconformality

   • V. V. Aseev

   OriginalPaper 23 September 2021 Pages: 782 - 795

3. On Categoricity Spectra for Locally Finite Graphs

   • N. A. Bazhenov
   • M. I. Marchuk

   OriginalPaper 23 September 2021 Pages: 796 - 804

4. On One Class of Systems of Differential Equations with Periodic Coefficients in Linear Terms

   • G. V. Demidenko

   OriginalPaper 23 September 2021 Pages: 805 - 821

5. A Semilattice of Degrees of Computable Metrics

   • R. A. Kornev

   OriginalPaper 23 September 2021 Pages: 822 - 841

6. On Sizes of 1-Cross Intersecting Set Pair Systems

   • A. V. Kostochka
   • G. McCourt
   • M. Nahvi

   OriginalPaper 23 September 2021 Pages: 842 - 849

   

7. Structure of Quasivariety Lattices. IV. Nonstandard Quasivarieties

   • A. V. Kravchenko
   • A. M. Nurakunov
   • M. V. Schwidefsky

   OriginalPaper 23 September 2021 Pages: 850 - 858

   

8. On Some Criteria of \( f \)-Hypercentral Actions of Finite Groups

   • B. Li
   • Q. Chen
   • C. Qiaolin

   OriginalPaper 23 September 2021 Pages: 859 - 867

9. A Dedekind Criterion over Valued Fields

   • L. El Fadil
   • M. Boulagouaz
   • A. Deajim

   OriginalPaper 23 September 2021 Pages: 868 - 875

10. Hybrid Extensions of the Minimal Logic

    • L. L. Maksimova
    • V. F. Yun

    OriginalPaper 23 September 2021 Pages: 876 - 881

11. New Degree Spectra of Polish Spaces

    • A. G. Melnikov

    OriginalPaper 23 September 2021 Pages: 882 - 894

12. Existence of Weak Solutions to the Problem on Three-Dimensional Steady Heat-Conductive Motions of Compressible Viscous Multicomponent Mixtures

    • D. A. Prokudin

    OriginalPaper 23 September 2021 Pages: 895 - 907

13. On Justification of the Gelfand–Levitan–Krein Method for a Two-Dimensional Inverse Problem

    • V. G. Romanov

    OriginalPaper 23 September 2021 Pages: 908 - 924

14. The Defect of a Cauchy Type Problem for Linear Equations with Several Riemann–Liouville Derivatives

    • V. E. Fedorov
    • M. M. Turov

    OriginalPaper 23 September 2021 Pages: 925 - 942

15. Poor Ideal Three-Edge Triangulations Are Minimal

    • E. A. Fominykh
    • E. V. Shumakova

    OriginalPaper 23 September 2021 Pages: 943 - 950

    

16. On the Number of Frequency Hypercubes F\( {}^{n}(4;2,2) \)

    • M. J. Shi
    • S. K. Wang
    • D. S. Krotov

    OriginalPaper 23 September 2021 Pages: 951 - 962