1. Best approximations and differential properties of two conjugate functions (in Russian);Bary;Proc. Moscow Math. Soc.,1956
2. L. Diening P. Hästö A. Nekvinda Open problems in variable exponent Lebesgue and Sobolev spaces, in: Function Spaces, Differential Operators and Nonlinear Analysis 2004
3. A. E. Gatto On fractional calculus associated to doubling and non-doubling measures 15 37
4. On fractional differentiation on spaces of homogeneous type;Gatto;Rev. Mat. Iberoam.,1996