BOUTERAA, N., & BENAICHA, S. (2020). Existence and multiplicity of positive radial solutions to the Dirichlet problem for nonlinear elliptic equations on annular domains. Studia Universitatis Babeș-Bolyai Mathematica, 65(1), 109–125. https://doi.org/10.24193/subbmath.2020.1.09