@misc{Valdar_Andy_The,
 author={Valdar, Andy},
 howpublished={online},
 publisher={National Institute of Telecommunications},
 language={ang},
 type={artykuł},
 title={The Potential Cyber and Network Security Issues of PSTN Closure, Journal of Telecommunications and Information Technology, 2025, Special Issue},
 keywords={all-IP NGN, IP phone, PTSN, VoIP},
}