Mizuta, Y., T. Ohno, T. Shimomuraand, and N. Shioji. “Compact Embeddings for Sobolev Spaces of Variable Exponents and Existence of Solutions for Nonlinear Elliptic Problems Involving the p(x)-Laplacian and Its Critical Exponent”. Annales Fennici Mathematici, vol. 35, no. 1, Feb. 2010, pp. 115-30, doi:10.5186/aasfm.2010.3507.