1. Adams, R.: Sobolev Spaces. Academic Press, New York (1975)
2. Ahmida, Y., Chlebicka, I., Gwiazda, P., Youssfi, A.: Gossez’s approximation theorems in Musielak–Orlicz–Sobolev spaces. J. Funct. Anal. (2018). https://doi.org/10.1016/j.jfa.2018.05.015
3. Alvino, A., Boccardo, L., Ferone, V., Orsina, L., Trombetti, G.: Existence results for nonlinear elliptic equations with degenerate coercivity. Ann. Mat. Pura Appl. IV. Ser. 182(1), 53–79 (2003)
4. Alvino, A., Ferone, V., Trombetti, G.: A priori estimates for a class of non uniformly elliptic equations. Atti Semin. Mat. Fis. Univ. Modena 46(suppl.), 381–391 (1998)
5. Ben Cheikh Ali, M., Guibé, O.: Nonlinear and non-coercive elliptic problems with integrable data (English summary). Adv. Math. Sci. Appl. 16(1), 275–297 (2006)