Al-Showbaki, Laith, et al. “Anti-Programmed Cell Death-1 Versus Anti-Programmed Death-Ligand 1 (PD-L1) in PD-L1-Negative Advanced Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis”. World Journal of Oncology, Apr. 2025, https://doi.org/10.14740/wjon2520.