On the Mathematical Works of S.L. Sobolev in the 1930s, V. Babich.- Sobolev in Siberia, Y. Reshetnyak.- Boundary Harnack Principle and the Quasihyperbolic Boundary Condition, H. Aikawa.- Sobolev Spaces and their Relatives: local Polynomial Approximation Approach, Y. Brudnyi.- Spectral Stability of Higher Order Uniformly Elliptic Operators, V. Burenkov, P.D. Lamberti.- Conductor Inequalities and Criteria for Sobolev - Lorentz Two - Weight Inequalities,...