Husain, Husain, et al. “Implementation of Port Knocking With Telegram Notifications to Protect Against Scanner Vulnerabilities”. MATRIK : Jurnal Manajemen, Teknik Informatika Dan Rekayasa Komputer, vol. 23, no. 1, Nov. 2023, pp. 215-28, https://doi.org/10.30812/matrik.v23i1.3459.