Farroni, F., R. Giova, G. Moscariello, and R. Schiattarella. “Homeomorphisms of Finite Inner Distortion: Composition Operators on Zygmund-Sobolev and Lorentz-Sobolev Spaces”. MATHEMATICA SCANDINAVICA, vol. 116, no. 1, Mar. 2015, pp. 34-52, doi:10.7146/math.scand.a-20450.