Nguyen, S.-Q. and Le, C.-B. 2025. Physical Layer Security for Keyhole-based NOMA Downlink Systems with a Multi-antenna Eavesdropper. Journal of Telecommunications and Information Technology. 101, 3 (Sep. 2025), 16–22. DOI:https://doi.org/10.26636/jtit.2025.3.2116.