OUCHENANE, D. et al. 2022. Global nonexistence of solution for coupled nonlinear Klein-Gordon with degenerate damping and source terms. Studia Universitatis Babeș-Bolyai Mathematica. 67, 4 (Dec. 2022), 801–815. DOI:https://doi.org/10.24193/subbmath.2022.4.10.